diff --git a/packages/core/admin/admin/src/content-manager/pages/ListView/index.js b/packages/core/admin/admin/src/content-manager/pages/ListView/index.js
index 7514849573..26c74c17c9 100644
--- a/packages/core/admin/admin/src/content-manager/pages/ListView/index.js
+++ b/packages/core/admin/admin/src/content-manager/pages/ListView/index.js
@@ -100,6 +100,7 @@ function ListView({
 
       try {
         const opts = source ? { cancelToken: source.token } : null;
+
         const {
           data: { results, pagination: paginationResult },
         } = await axiosInstance.get(endPoint, opts);
diff --git a/packages/core/admin/admin/src/content-manager/pages/ListView/utils/buildQueryString.js b/packages/core/admin/admin/src/content-manager/pages/ListView/utils/buildQueryString.js
index 632fe1bd03..9fbe60820f 100644
--- a/packages/core/admin/admin/src/content-manager/pages/ListView/utils/buildQueryString.js
+++ b/packages/core/admin/admin/src/content-manager/pages/ListView/utils/buildQueryString.js
@@ -4,19 +4,16 @@ import createPluginsFilter from './createPluginsFilter';
 /**
  * Creates a valid query string from an object of queryParams
  * This includes:
- * - a _where clause
+ * - a filters clause
  * - plugin options
  */
 const buildQueryString = (queryParams = {}) => {
-  const _where = queryParams._where || [];
-
   /**
    * Extracting pluginOptions from the query since we don't want them to be part
    * of the url
    */
   const { plugins: _, ...otherQueryParams } = {
     ...queryParams,
-    _where,
     ...createPluginsFilter(queryParams.plugins),
   };
 
diff --git a/packages/core/admin/admin/src/content-manager/pages/ListView/utils/createPluginsFilter.js b/packages/core/admin/admin/src/content-manager/pages/ListView/utils/createPluginsFilter.js
index caa2420b73..57571928b2 100644
--- a/packages/core/admin/admin/src/content-manager/pages/ListView/utils/createPluginsFilter.js
+++ b/packages/core/admin/admin/src/content-manager/pages/ListView/utils/createPluginsFilter.js
@@ -1,13 +1,4 @@
 const createPluginsFilter = obj =>
-  Object.values(obj || {}).reduce((acc, current) => {
-    return {
-      ...acc,
-      ...Object.keys(current).reduce((accumulator, key) => {
-        accumulator[`_${key}`] = current[key];
-
-        return accumulator;
-      }, {}),
-    };
-  }, {});
+  Object.values(obj || {}).reduce((acc, current) => Object.assign(acc, current), {});
 
 export default createPluginsFilter;
diff --git a/packages/core/admin/admin/src/content-manager/pages/ListView/utils/tests/buildQueryString.test.js b/packages/core/admin/admin/src/content-manager/pages/ListView/utils/tests/buildQueryString.test.js
index 19dc020199..2236be012e 100644
--- a/packages/core/admin/admin/src/content-manager/pages/ListView/utils/tests/buildQueryString.test.js
+++ b/packages/core/admin/admin/src/content-manager/pages/ListView/utils/tests/buildQueryString.test.js
@@ -25,28 +25,28 @@ describe('buildQueryString', () => {
 
     const queryString = buildQueryString(queryParams);
 
-    expect(queryString).toBe('?page=1&pageSize=10&sort=name:ASC&_locale=en');
+    expect(queryString).toBe('?page=1&pageSize=10&sort=name:ASC&locale=en');
   });
 
-  it('creates a valid query string with a _where clause', () => {
+  it('creates a valid query string with a filters clause', () => {
     const queryParams = {
       page: '1',
       pageSize: '10',
       sort: 'name:ASC',
-      _where: [{ name: 'hello world' }],
+      filters: [{ name: 'hello world' }],
     };
 
     const queryString = buildQueryString(queryParams);
 
-    expect(queryString).toBe('?page=1&pageSize=10&sort=name:ASC&_where[0][name]=hello world');
+    expect(queryString).toBe('?page=1&pageSize=10&sort=name:ASC&filters[0][name]=hello world');
   });
 
-  it('creates a valid query string with a _where and plugin options', () => {
+  it('creates a valid query string with a filters and plugin options', () => {
     const queryParams = {
       page: '1',
       pageSize: '10',
       sort: 'name:ASC',
-      _where: [{ name: 'hello world' }],
+      filters: [{ name: 'hello world' }],
       plugins: {
         i18n: { locale: 'en' },
       },
@@ -55,7 +55,7 @@ describe('buildQueryString', () => {
     const queryString = buildQueryString(queryParams);
 
     expect(queryString).toBe(
-      '?page=1&pageSize=10&sort=name:ASC&_where[0][name]=hello world&_locale=en'
+      '?page=1&pageSize=10&sort=name:ASC&filters[0][name]=hello world&locale=en'
     );
   });
 });
diff --git a/packages/core/admin/admin/src/content-manager/utils/formatFiltersFromQuery.js b/packages/core/admin/admin/src/content-manager/utils/formatFiltersFromQuery.js
deleted file mode 100644
index 39c260e28e..0000000000
--- a/packages/core/admin/admin/src/content-manager/utils/formatFiltersFromQuery.js
+++ /dev/null
@@ -1,55 +0,0 @@
-// List of all the possible filters
-const VALID_REST_OPERATORS = [
-  'eq',
-  'ne',
-  'in',
-  'nin',
-  'contains',
-  'ncontains',
-  'containss',
-  'ncontainss',
-  'lt',
-  'lte',
-  'gt',
-  'gte',
-  'null',
-];
-
-// from strapi-utils/convert-rest-query-params
-const findAppliedFilter = whereClause => {
-  // Useful to remove the mainField of relation fields.
-  const formattedWhereClause = whereClause.split('.')[0];
-  const separatorIndex = whereClause.lastIndexOf('_');
-
-  if (separatorIndex === -1) {
-    return { operator: '=', field: formattedWhereClause };
-  }
-
-  const fieldName = formattedWhereClause.substring(0, separatorIndex);
-  const operator = whereClause.slice(separatorIndex + 1);
-
-  // the field as underscores
-  if (!VALID_REST_OPERATORS.includes(operator)) {
-    return { operator: '=', field: formattedWhereClause };
-  }
-
-  return { operator: `_${operator}`, field: fieldName };
-};
-
-const formatFiltersFromQuery = ({ _where }) => {
-  if (!_where) {
-    return [];
-  }
-
-  return _where.map(obj => {
-    const [key] = Object.keys(obj);
-    const { field, operator } = findAppliedFilter(key);
-
-    const value = obj[key];
-
-    return { name: field, filter: operator, value };
-  });
-};
-
-export default formatFiltersFromQuery;
-export { findAppliedFilter };
diff --git a/packages/core/admin/admin/src/content-manager/utils/formatFiltersToQuery.js b/packages/core/admin/admin/src/content-manager/utils/formatFiltersToQuery.js
deleted file mode 100644
index d64ab966a2..0000000000
--- a/packages/core/admin/admin/src/content-manager/utils/formatFiltersToQuery.js
+++ /dev/null
@@ -1,27 +0,0 @@
-import { get } from 'lodash';
-
-const formatFilterName = (name, metadatas) => {
-  const mainField = get(metadatas, [name, 'list', 'mainField', 'name'], null);
-
-  if (mainField) {
-    return `${name}.${mainField}`;
-  }
-
-  return name;
-};
-
-const formatFiltersToQuery = (array, metadatas) => {
-  const nextFilters = array.map(({ name, filter, value }) => {
-    const formattedName = formatFilterName(name, metadatas);
-
-    if (filter === '=') {
-      return { [formattedName]: value };
-    }
-
-    return { [`${formattedName}${filter}`]: value };
-  });
-
-  return { _where: nextFilters };
-};
-
-export default formatFiltersToQuery;
diff --git a/packages/core/admin/admin/src/content-manager/utils/index.js b/packages/core/admin/admin/src/content-manager/utils/index.js
index 8d3eb9272d..a916121406 100644
--- a/packages/core/admin/admin/src/content-manager/utils/index.js
+++ b/packages/core/admin/admin/src/content-manager/utils/index.js
@@ -2,8 +2,6 @@ export { default as arrayMoveItem } from './arrayMoveItem';
 export { default as checkIfAttributeIsDisplayable } from './checkIfAttributeIsDisplayable';
 export { default as createDefaultForm } from './createDefaultForm';
 export { default as dateFormats } from './dateFormats';
-export { default as formatFiltersFromQuery } from './formatFiltersFromQuery';
-export { default as formatFiltersToQuery } from './formatFiltersToQuery';
 export { default as formatLayoutToApi } from './formatLayoutToApi';
 export { default as generatePermissionsObject } from './generatePermissionsObject';
 export { default as getDisplayedValue } from './getDisplayedValue';
diff --git a/packages/core/admin/admin/src/content-manager/utils/tests/formatFilterFromQuery.test.js b/packages/core/admin/admin/src/content-manager/utils/tests/formatFilterFromQuery.test.js
deleted file mode 100644
index a1b21305cd..0000000000
--- a/packages/core/admin/admin/src/content-manager/utils/tests/formatFilterFromQuery.test.js
+++ /dev/null
@@ -1,66 +0,0 @@
-import formatFiltersFromQuery, { findAppliedFilter } from '../formatFiltersFromQuery';
-
-describe('CONTENT MANAGER | utils', () => {
-  describe('findAppliedFilter', () => {
-    it('should return the correct filter', () => {
-      expect(findAppliedFilter('categories.name')).toEqual({ operator: '=', field: 'categories' });
-      expect(findAppliedFilter('categories.name_lt')).toEqual({
-        operator: '_lt',
-        field: 'categories',
-      });
-      expect(findAppliedFilter('city')).toEqual({ operator: '=', field: 'city' });
-      expect(findAppliedFilter('city_nee')).toEqual({ operator: '=', field: 'city_nee' });
-      expect(findAppliedFilter('city_ne')).toEqual({ operator: '_ne', field: 'city' });
-      expect(findAppliedFilter('city_lt')).toEqual({ operator: '_lt', field: 'city' });
-      expect(findAppliedFilter('city_lte')).toEqual({ operator: '_lte', field: 'city' });
-      expect(findAppliedFilter('city_gt')).toEqual({ operator: '_gt', field: 'city' });
-      expect(findAppliedFilter('city_gte')).toEqual({ operator: '_gte', field: 'city' });
-    });
-  });
-
-  describe('formatFiltersFromQuery', () => {
-    it('should return an empty array if there is no where clause', () => {
-      expect(formatFiltersFromQuery({})).toHaveLength(0);
-    });
-
-    it('should return array of filter', () => {
-      const query = {
-        _where: [
-          {
-            city_ne_ne: 'paris',
-          },
-          {
-            city_ne: 'paris',
-          },
-          {
-            city: 'paris',
-          },
-          {
-            'categories.name_ne': 'first',
-          },
-          {
-            'like.numbers_lt': 34,
-          },
-        ],
-      };
-
-      const expected = [
-        { name: 'city_ne', filter: '_ne', value: 'paris' },
-        { name: 'city', filter: '_ne', value: 'paris' },
-        { name: 'city', filter: '=', value: 'paris' },
-        {
-          name: 'categories',
-          filter: '_ne',
-          value: 'first',
-        },
-        {
-          name: 'like',
-          filter: '_lt',
-          value: 34,
-        },
-      ];
-
-      expect(formatFiltersFromQuery(query)).toEqual(expected);
-    });
-  });
-});
diff --git a/packages/core/admin/admin/src/content-manager/utils/tests/formatFiltersToQuery.test.js b/packages/core/admin/admin/src/content-manager/utils/tests/formatFiltersToQuery.test.js
deleted file mode 100644
index b0e8cbba69..0000000000
--- a/packages/core/admin/admin/src/content-manager/utils/tests/formatFiltersToQuery.test.js
+++ /dev/null
@@ -1,57 +0,0 @@
-import formatFiltersToQuery from '../formatFiltersToQuery';
-
-describe('CONTENT MANAGER | utils', () => {
-  describe('formatFiltersToQuery', () => {
-    it('should return the filters query', () => {
-      const metadatas = {
-        categories: {
-          list: {
-            mainField: { name: 'name' },
-          },
-        },
-        like: {
-          list: {
-            mainField: { name: 'numbers' },
-          },
-        },
-      };
-      const data = [
-        { name: 'city_ne', filter: '_ne', value: 'paris' },
-        { name: 'city', filter: '_ne', value: 'paris' },
-        { name: 'city', filter: '=', value: 'paris' },
-        {
-          name: 'categories',
-          filter: '_ne',
-          value: 'first',
-        },
-        {
-          name: 'like',
-          filter: '_lt',
-          value: 34,
-        },
-      ];
-
-      const expected = {
-        _where: [
-          {
-            city_ne_ne: 'paris',
-          },
-          {
-            city_ne: 'paris',
-          },
-          {
-            city: 'paris',
-          },
-          {
-            'categories.name_ne': 'first',
-          },
-          {
-            'like.numbers_lt': 34,
-          },
-        ],
-      };
-
-      expect(formatFiltersToQuery(data, metadatas)).toEqual(expected);
-    });
-  });
-});
diff --git a/packages/core/content-manager/server/controllers/collection-types.js b/packages/core/content-manager/server/controllers/collection-types.js
index 07e1649422..84037dbc54 100644
--- a/packages/core/content-manager/server/controllers/collection-types.js
+++ b/packages/core/content-manager/server/controllers/collection-types.js
@@ -223,7 +223,7 @@ module.exports = {
     const params = {
       ...permissionQuery,
       filters: {
-        $and: [idsWhereClause].concat(permissionQuery._where || []),
+        $and: [idsWhereClause].concat(permissionQuery.filters || []),
       },
     };
 
diff --git a/packages/core/database/lib/entity-manager.js b/packages/core/database/lib/entity-manager.js
index d0d79dab5c..c614e5a4e7 100644
--- a/packages/core/database/lib/entity-manager.js
+++ b/packages/core/database/lib/entity-manager.js
@@ -142,7 +142,7 @@ const createEntityManager = db => {
       await db.lifecycles.run('beforeCount', uid, { params });
 
       const res = await this.createQueryBuilder(uid)
-        .init(_.pick(['_q', 'where'], params))
+        .init(_.pick(['_q', 'where', 'filters'], params))
         .count()
         .first()
         .execute();
@@ -172,7 +172,7 @@ const createEntityManager = db => {
 
       await this.attachRelations(uid, id, data);
 
-      // TODO: in case there is not select or populate specified return the inserted data ?
+      // TODO: in case there is no select or populate specified return the inserted data ?
       // TODO: do not trigger the findOne lifecycles ?
       const result = await this.findOne(uid, {
         where: { id },
@@ -296,7 +296,7 @@ const createEntityManager = db => {
         throw new Error('Delete requires a where parameter');
       }
 
-      // TODO: avoid trigger the findOne lifecycles in the case ?
+      // TODO: do not trigger the findOne lifecycles ?
       const entity = await this.findOne(uid, {
         select: select && ['id'].concat(select),
         where,
@@ -469,7 +469,6 @@ const createEntityManager = db => {
           const { joinTable } = attribute;
           const { joinColumn, inverseJoinColumn } = joinTable;
 
-          // TODO: validate logic of delete
           if (isOneToAny(attribute) && isBidirectional(attribute)) {
             await this.createQueryBuilder(joinTable.name)
               .delete()
diff --git a/packages/core/database/lib/query/helpers/populate.js b/packages/core/database/lib/query/helpers/populate.js
index eca5d12b97..b8740e2458 100644
--- a/packages/core/database/lib/query/helpers/populate.js
+++ b/packages/core/database/lib/query/helpers/populate.js
@@ -122,7 +122,11 @@ const applyPopulate = async (results, populate, ctx) => {
     const attribute = meta.attributes[key];
     const targetMeta = db.metadata.get(attribute.target);
 
-    const populateValue = pickPopulateParams(populate[key]);
+    const populateValue = {
+      ...pickPopulateParams(populate[key]),
+      filters: qb.state.filters,
+    };
+
     const isCount = populateValue.count === true;
 
     const fromTargetRow = rowOrRows => fromRow(targetMeta, rowOrRows);
diff --git a/packages/core/database/lib/query/query-builder.js b/packages/core/database/lib/query/query-builder.js
index 715ec8f493..b559a0a378 100644
--- a/packages/core/database/lib/query/query-builder.js
+++ b/packages/core/database/lib/query/query-builder.js
@@ -29,6 +29,7 @@ const createQueryBuilder = (uid, db) => {
   return {
     alias: getAlias(),
     getAlias,
+    state,
 
     select(args) {
       state.type = 'select';
@@ -115,7 +116,7 @@ const createQueryBuilder = (uid, db) => {
     },
 
     init(params = {}) {
-      const { _q, where, select, limit, offset, orderBy, groupBy, populate } = params;
+      const { _q, filters, where, select, limit, offset, orderBy, groupBy, populate } = params;
 
       if (!_.isNil(where)) {
         this.where(where);
@@ -151,9 +152,17 @@ const createQueryBuilder = (uid, db) => {
         this.populate(populate);
       }
 
+      if (!_.isNil(filters)) {
+        this.filters(filters);
+      }
+
       return this;
     },
 
+    filters(filters) {
+      state.filters = filters;
+    },
+
     first() {
       state.first = true;
       return this;
@@ -206,6 +215,19 @@ const createQueryBuilder = (uid, db) => {
 
     processState() {
       state.orderBy = helpers.processOrderBy(state.orderBy, { qb: this, uid, db });
+
+      if (!_.isNil(state.filters)) {
+        if (_.isFunction(state.filters)) {
+          const filters = state.filters({ qb: this, uid, meta, db });
+
+          if (!_.isNil(filters)) {
+            state.where.push(filters);
+          }
+        } else {
+          state.where.push(state.filters);
+        }
+      }
+
       state.where = helpers.processWhere(state.where, { qb: this, uid, db });
       state.populate = helpers.processPopulate(state.populate, { qb: this, uid, db });
       state.data = helpers.toRow(meta, state.data);
diff --git a/packages/core/strapi/lib/Strapi.js b/packages/core/strapi/lib/Strapi.js
index e0e2c00b04..08ea1c6396 100644
--- a/packages/core/strapi/lib/Strapi.js
+++ b/packages/core/strapi/lib/Strapi.js
@@ -259,7 +259,7 @@ class Strapi {
   }
 
   stop(exitCode = 1) {
-    this.server.destroy();
+    this.destroy();
 
     if (this.config.get('autoReload')) {
       process.send('stop');
@@ -431,7 +431,6 @@ class Strapi {
       }
 
       if (this.config.get('autoReload')) {
-        this.destroy();
         process.send('reload');
       }
     };
diff --git a/packages/core/strapi/lib/commands/develop.js b/packages/core/strapi/lib/commands/develop.js
index e8d39193d1..aa96471a3b 100644
--- a/packages/core/strapi/lib/commands/develop.js
+++ b/packages/core/strapi/lib/commands/develop.js
@@ -52,14 +52,12 @@ module.exports = async function({ build, watchAdmin, polling, browser }) {
         switch (message) {
           case 'reload':
             logger.info('The server is restarting\n');
-            worker.send('isKilled');
+            worker.send('kill');
             break;
-          case 'kill':
-            worker.kill();
+          case 'killed':
             cluster.fork();
             break;
           case 'stop':
-            worker.kill();
             process.exit(1);
           default:
             return;
@@ -85,10 +83,10 @@ module.exports = async function({ build, watchAdmin, polling, browser }) {
 
       process.on('message', async message => {
         switch (message) {
-          case 'isKilled':
-            await strapiInstance.server.destroy();
-            process.send('kill');
-            break;
+          case 'kill':
+            await strapiInstance.destroy();
+            process.send('killed');
+            process.exit();
           default:
           // Do nothing.
         }
diff --git a/packages/core/strapi/lib/services/entity-service/__tests__/entity-service.test.js b/packages/core/strapi/lib/services/entity-service/__tests__/entity-service.test.js
index 6428d053dc..5ad4924b55 100644
--- a/packages/core/strapi/lib/services/entity-service/__tests__/entity-service.test.js
+++ b/packages/core/strapi/lib/services/entity-service/__tests__/entity-service.test.js
@@ -1,6 +1,6 @@
 'use strict';
 
-jest.mock('bcrypt', () => ({ hashSync: () => 'secret-password' }));
+jest.mock('bcryptjs', () => ({ hashSync: () => 'secret-password' }));
 
 const { EventEmitter } = require('events');
 const createEntityService = require('../');
diff --git a/packages/core/strapi/lib/services/entity-service/attributes/transforms.js b/packages/core/strapi/lib/services/entity-service/attributes/transforms.js
index 406a622123..c2e40b808c 100644
--- a/packages/core/strapi/lib/services/entity-service/attributes/transforms.js
+++ b/packages/core/strapi/lib/services/entity-service/attributes/transforms.js
@@ -1,7 +1,7 @@
 'use strict';
 
 const { getOr, toNumber, isString, isBuffer } = require('lodash/fp');
-const bcrypt = require('bcrypt');
+const bcrypt = require('bcryptjs');
 
 const transforms = {
   password(value, context) {
diff --git a/packages/core/strapi/lib/services/entity-service/index.js b/packages/core/strapi/lib/services/entity-service/index.js
index e37228c56d..b37071098a 100644
--- a/packages/core/strapi/lib/services/entity-service/index.js
+++ b/packages/core/strapi/lib/services/entity-service/index.js
@@ -1,7 +1,6 @@
 'use strict';
 
 const delegate = require('delegates');
-const { pipe } = require('lodash/fp');
 
 const {
   sanitizeEntity,
@@ -16,12 +15,7 @@ const {
   updateComponents,
   deleteComponents,
 } = require('./components');
-const {
-  transformCommonParams,
-  transformPaginationParams,
-  transformParamsToQuery,
-  pickSelectionParams,
-} = require('./params');
+const { transformParamsToQuery, pickSelectionParams } = require('./params');
 const { applyTransforms } = require('./attributes');
 
 // TODO: those should be strapi events used by the webhooks not the other way arround
@@ -244,13 +238,26 @@ const createDefaultImplementation = ({ strapi, db, eventHub, entityValidator })
 
     const attribute = attributes[field];
 
-    const loadParams =
-      attribute.type === 'relation'
-        ? transformParamsToQuery(attribute.target, params)
-        : pipe(
-            transformCommonParams,
-            transformPaginationParams
-          )(params);
+    const loadParams = {};
+
+    switch (attribute.type) {
+      case 'relation': {
+        Object.assign(loadParams, transformParamsToQuery(attribute.target, params));
+        break;
+      }
+      case 'component': {
+        Object.assign(loadParams, transformParamsToQuery(attribute.component, params));
+        break;
+      }
+      case 'dynamiczone': {
+        Object.assign(loadParams, transformParamsToQuery(null, params));
+        break;
+      }
+      case 'media': {
+        Object.assign(loadParams, transformParamsToQuery('plugin::upload.file', params));
+        break;
+      }
+    }
 
     return db.query(uid).load(entity, field, loadParams);
   },
diff --git a/packages/core/strapi/lib/services/entity-service/params.js b/packages/core/strapi/lib/services/entity-service/params.js
index a7ef523798..877d6a5f13 100644
--- a/packages/core/strapi/lib/services/entity-service/params.js
+++ b/packages/core/strapi/lib/services/entity-service/params.js
@@ -1,6 +1,7 @@
 'use strict';
 
-const { pick, pipe, isNil } = require('lodash/fp');
+const assert = require('assert').strict;
+const { pick, isNil, toNumber, isInteger } = require('lodash/fp');
 
 const {
   convertSortQueryParams,
@@ -9,62 +10,39 @@ const {
   convertPopulateQueryParams,
   convertFiltersQueryParams,
   convertFieldsQueryParams,
+  convertPublicationStateParams,
 } = require('@strapi/utils/lib/convert-query-params');
 
-const { contentTypes: contentTypesUtils } = require('@strapi/utils');
+const pickSelectionParams = pick(['fields', 'populate']);
 
-const { PUBLISHED_AT_ATTRIBUTE } = contentTypesUtils.constants;
+const transformParamsToQuery = (uid, params) => {
+  // NOTE: can be a CT, a Compo or nothing in the case of polymorphism (DZ & morph relations)
+  const type = strapi.getModel(uid);
 
-// TODO: to remove once the front is migrated
-const convertOldQuery = params => {
   const query = {};
 
-  Object.keys(params).forEach(key => {
-    if (key.startsWith('_')) {
-      query[key.slice(1)] = params[key];
-    } else {
-      query[key] = params[key];
-    }
-  });
+  const { _q, sort, filters, fields, populate, page, pageSize, start, limit } = params;
 
-  return query;
-};
-
-const transformCommonParams = (params = {}) => {
-  const { _q, sort, filters, _where, fields, populate, ...query } = params;
-
-  if (_q) {
+  if (!isNil(_q)) {
     query._q = _q;
   }
 
-  if (sort) {
+  if (!isNil(sort)) {
     query.orderBy = convertSortQueryParams(sort);
   }
 
-  if (filters) {
+  if (!isNil(filters)) {
     query.where = convertFiltersQueryParams(filters);
   }
 
-  if (_where) {
-    query.where = {
-      $and: [_where].concat(query.where || []),
-    };
-  }
-
-  if (fields) {
+  if (!isNil(fields)) {
     query.select = convertFieldsQueryParams(fields);
   }
 
-  if (populate) {
+  if (!isNil(populate)) {
     query.populate = convertPopulateQueryParams(populate);
   }
 
-  return { ...convertOldQuery(query), ...query };
-};
-
-const transformPaginationParams = (params = {}) => {
-  const { page, pageSize, start, limit, ...query } = params;
-
   const isPagePagination = !isNil(page) || !isNil(pageSize);
   const isOffsetPagination = !isNil(start) || !isNil(limit);
 
@@ -74,72 +52,38 @@ const transformPaginationParams = (params = {}) => {
     );
   }
 
-  if (page) {
-    query.page = Number(page);
+  if (!isNil(page)) {
+    const pageVal = toNumber(page);
+    const isValid = isInteger(pageVal) && pageVal > 0;
+
+    assert(isValid, `Invalid 'page' parameter. Expected an integer > 0, received: ${page}`);
+
+    query.page = pageVal;
   }
 
-  if (pageSize) {
-    query.pageSize = Number(pageSize);
+  if (!isNil(pageSize)) {
+    const pageSizeVal = toNumber(pageSize);
+    const isValid = isInteger(pageSizeVal) && pageSizeVal > 0;
+
+    assert(isValid, `Invalid 'pageSize' parameter. Expected an integer > 0, received: ${page}`);
+
+    query.pageSize = pageSizeVal;
   }
 
-  if (start) {
+  if (!isNil(start)) {
     query.offset = convertStartQueryParams(start);
   }
 
-  if (limit) {
+  if (!isNil(limit)) {
     query.limit = convertLimitQueryParams(limit);
   }
 
-  return { ...convertOldQuery(query), ...query };
-};
+  convertPublicationStateParams(type, params, query);
 
-const transformPublicationStateParams = uid => (params = {}) => {
-  const contentType = strapi.getModel(uid);
-
-  if (!contentType) {
-    return params;
-  }
-
-  const { publicationState, ...query } = params;
-
-  if (publicationState && contentTypesUtils.hasDraftAndPublish(contentType)) {
-    const { publicationState = 'live' } = params;
-
-    const liveClause = {
-      [PUBLISHED_AT_ATTRIBUTE]: {
-        $notNull: true,
-      },
-    };
-
-    if (publicationState === 'live') {
-      query.where = {
-        $and: [liveClause].concat(query.where || []),
-      };
-
-      // TODO: propagate nested publicationState filter somehow
-    }
-  }
-
-  return { ...convertOldQuery(query), ...query };
-};
-
-const pickSelectionParams = pick(['fields', 'populate']);
-
-const transformParamsToQuery = (uid, params) => {
-  return pipe(
-    // _q, _where, filters, etc...
-    transformCommonParams,
-    // page, pageSize, start, limit
-    transformPaginationParams,
-    // publicationState
-    transformPublicationStateParams(uid)
-  )(params);
+  return query;
 };
 
 module.exports = {
-  transformCommonParams,
-  transformPublicationStateParams,
-  transformPaginationParams,
   transformParamsToQuery,
   pickSelectionParams,
 };
diff --git a/packages/core/strapi/lib/utils/signals.js b/packages/core/strapi/lib/utils/signals.js
index 5a8b05af34..65e539721d 100644
--- a/packages/core/strapi/lib/utils/signals.js
+++ b/packages/core/strapi/lib/utils/signals.js
@@ -1,6 +1,6 @@
 'use strict';
 
-const destroyOnSignal = () => {
+const destroyOnSignal = strapi => {
   let signalReceived = false;
 
   // For unknown reasons, we receive signals 2 times.
diff --git a/packages/core/strapi/package.json b/packages/core/strapi/package.json
index 164f5250ee..df0e8ed4f7 100644
--- a/packages/core/strapi/package.json
+++ b/packages/core/strapi/package.json
@@ -90,7 +90,7 @@
     "@strapi/plugin-email": "3.6.8",
     "@strapi/plugin-upload": "3.6.8",
     "@strapi/utils": "3.6.8",
-    "bcrypt": "5.0.1",
+    "bcryptjs": "2.4.3",
     "boxen": "5.1.2",
     "chalk": "4.1.2",
     "chokidar": "3.5.2",
diff --git a/packages/core/strapi/tests/publication-state.test.e2e.js b/packages/core/strapi/tests/publication-state.test.e2e.js
index 999da335b6..80fcf9f548 100644
--- a/packages/core/strapi/tests/publication-state.test.e2e.js
+++ b/packages/core/strapi/tests/publication-state.test.e2e.js
@@ -171,6 +171,7 @@ describe('Publication State', () => {
         const res = await rq({ method: 'GET', url: `${baseUrl}${query}` });
 
         expect(res.body.data).toHaveLength(lengthFor(modelName, { mode }));
+
         expect(res.body.meta.pagination.total).toBe(lengthFor(modelName, { mode }));
       });
     });
@@ -190,7 +191,7 @@ describe('Publication State', () => {
           },
         });
 
-        products = res.body.data.map(res => ({ id: res.id, ...res.attributes }));
+        products = res.body.data;
       });
 
       test('Payload integrity', () => {
@@ -199,35 +200,29 @@ describe('Publication State', () => {
 
       test('Root level', () => {
         products.forEach(product => {
-          expect(product.publishedAt).toBeISODate();
+          expect(product.attributes.publishedAt).toBeISODate();
         });
       });
 
-      // const getApiRef = id => data.product.find(product => product.id === id);
+      test('First level (categories) to be published only', () => {
+        products.forEach(({ attributes }) => {
+          const categories = attributes.categories.data;
 
-      test.todo('First level (categories)');
+          categories.forEach(category => {
+            expect(category.attributes.publishedAt).toBeISODate();
+          });
+        });
+      });
 
-      //   products.forEach(({ id, categories }) => {
-      //     const length = getApiRef(id).categories.filter(c => c.publishedAt !== null).length;
-      //     expect(categories).toHaveLength(length);
+      test('Second level through component (countries) to be published only', () => {
+        products.forEach(({ attributes }) => {
+          const countries = attributes.comp.countries.data;
 
-      //     categories.forEach(category => {
-      //       expect(category.publishedAt).toBeISODate();
-      //     });
-      //   });
-      // });
-
-      test.todo('Second level through component (countries)');
-
-      //   products.forEach(({ id, comp: { countries } }) => {
-      //     const length = getApiRef(id).comp.countries.filter(c => c.publishedAt !== null).length;
-      //     expect(countries).toHaveLength(length);
-
-      //     countries.forEach(country => {
-      //       expect(country.publishedAt).toBeISODate();
-      //     });
-      //   });
-      // });
+          countries.forEach(country => {
+            expect(country.attributes.publishedAt).toBeISODate();
+          });
+        });
+      });
     });
   });
 });
diff --git a/packages/core/utils/lib/convert-query-params.js b/packages/core/utils/lib/convert-query-params.js
index 9de8c2ca51..e4c9f94763 100644
--- a/packages/core/utils/lib/convert-query-params.js
+++ b/packages/core/utils/lib/convert-query-params.js
@@ -4,11 +4,12 @@
  * Converts the standard Strapi REST query params to a more usable format for querying
  * You can read more here: https://strapi.io/documentation/developer-docs/latest/developer-resources/content-api/content-api.html#filters
  */
-
+const { has } = require('lodash/fp');
 const _ = require('lodash');
 const parseType = require('./parse-type');
+const contentTypesUtils = require('./content-types');
 
-const QUERY_OPERATORS = ['_where', '_or', '_and'];
+const { PUBLISHED_AT_ATTRIBUTE } = contentTypesUtils.constants;
 
 class InvalidOrderError extends Error {
   constructor() {
@@ -132,13 +133,15 @@ const convertPopulateQueryParams = (populate, depth = 0) => {
 
   if (Array.isArray(populate)) {
     // map convert
-    return populate.flatMap(value => {
-      if (typeof value !== 'string') {
-        throw new InvalidPopulateError();
-      }
+    return _.uniq(
+      populate.flatMap(value => {
+        if (typeof value !== 'string') {
+          throw new InvalidPopulateError();
+        }
 
-      return value.split(',').map(value => _.trim(value));
-    });
+        return value.split(',').map(value => _.trim(value));
+      })
+    );
   }
 
   if (_.isPlainObject(populate)) {
@@ -146,6 +149,7 @@ const convertPopulateQueryParams = (populate, depth = 0) => {
     for (const key in populate) {
       transformedPopulate[key] = convertNestedPopulate(populate[key]);
     }
+
     return transformedPopulate;
   }
 
@@ -212,9 +216,31 @@ const convertFieldsQueryParams = (fields, depth = 0) => {
   throw new Error('Invalid fields parameter. Expected a string or an array of strings');
 };
 
-// NOTE: We could validate the parameters are on existing / non private attributes
 const convertFiltersQueryParams = filters => filters;
 
+const convertPublicationStateParams = (type, params = {}, query = {}) => {
+  if (!type) {
+    return;
+  }
+
+  const { publicationState } = params;
+
+  if (!_.isNil(publicationState)) {
+    if (!contentTypesUtils.constants.DP_PUB_STATES.includes(publicationState)) {
+      throw new Error(
+        `Invalid publicationState. Expected one of 'preview','live' received: ${publicationState}.`
+      );
+    }
+
+    // NOTE: this is the query layer filters not the entity service filters
+    query.filters = ({ meta }) => {
+      if (publicationState === 'live' && has(PUBLISHED_AT_ATTRIBUTE, meta.attributes)) {
+        return { [PUBLISHED_AT_ATTRIBUTE]: { $notNull: true } };
+      }
+    };
+  }
+};
+
 module.exports = {
   convertSortQueryParams,
   convertStartQueryParams,
@@ -222,5 +248,5 @@ module.exports = {
   convertPopulateQueryParams,
   convertFiltersQueryParams,
   convertFieldsQueryParams,
-  QUERY_OPERATORS,
+  convertPublicationStateParams,
 };
diff --git a/packages/core/utils/lib/index.js b/packages/core/utils/lib/index.js
index c6b8bde425..a7ddbea9ab 100644
--- a/packages/core/utils/lib/index.js
+++ b/packages/core/utils/lib/index.js
@@ -4,7 +4,6 @@
  * Export shared utilities
  */
 const { buildQuery, hasDeepFilters } = require('./build-query');
-const { QUERY_OPERATORS } = require('./convert-query-params');
 const parseMultipartData = require('./parse-multipart');
 const sanitizeEntity = require('./sanitize-entity');
 const parseType = require('./parse-type');
@@ -38,7 +37,6 @@ module.exports = {
   formatYupErrors,
   policy,
   templateConfiguration,
-  QUERY_OPERATORS,
   buildQuery,
   hasDeepFilters,
   parseMultipartData,
diff --git a/packages/plugins/i18n/admin/src/contentManagerHooks/mutateEditViewLayout.js b/packages/plugins/i18n/admin/src/contentManagerHooks/mutateEditViewLayout.js
index defae91c07..77ca58e9de 100644
--- a/packages/plugins/i18n/admin/src/contentManagerHooks/mutateEditViewLayout.js
+++ b/packages/plugins/i18n/admin/src/contentManagerHooks/mutateEditViewLayout.js
@@ -19,7 +19,7 @@ const enhanceRelationLayout = (layout, locale) =>
     if (get(current, ['targetModelPluginOptions', 'i18n', 'localized'], false)) {
       queryInfos = {
         ...queryInfos,
-        defaultParams: { ...queryInfos.defaultParams, _locale: locale },
+        defaultParams: { ...queryInfos.defaultParams, locale },
         paramsToKeep: ['plugins.i18n.locale'],
       };
     }
@@ -82,7 +82,7 @@ const enhanceComponentLayoutForRelations = (layout, locale) =>
       ) {
         const queryInfos = {
           ...field.queryInfos,
-          defaultParams: { ...field.queryInfos.defaultParams, _locale: locale },
+          defaultParams: { ...field.queryInfos.defaultParams, locale },
           paramsToKeep: ['plugins.i18n.locale'],
         };
 
diff --git a/packages/plugins/i18n/admin/src/contentManagerHooks/tests/mutateEditViewLayout.test.js b/packages/plugins/i18n/admin/src/contentManagerHooks/tests/mutateEditViewLayout.test.js
index 19a401c91d..49718a9814 100644
--- a/packages/plugins/i18n/admin/src/contentManagerHooks/tests/mutateEditViewLayout.test.js
+++ b/packages/plugins/i18n/admin/src/contentManagerHooks/tests/mutateEditViewLayout.test.js
@@ -277,7 +277,7 @@ describe('i18n | contentManagerHooks | mutateEditViewLayout', () => {
                   fieldSchema: { type: 'relation' },
                   targetModelPluginOptions: { i18n: { localized: true } },
                   queryInfos: {
-                    defaultParams: { test: true, _locale: 'en' },
+                    defaultParams: { test: true, locale: 'en' },
                     paramsToKeep: ['plugins.i18n.locale'],
                   },
                 },
@@ -299,7 +299,7 @@ describe('i18n | contentManagerHooks | mutateEditViewLayout', () => {
                   fieldSchema: { type: 'relation' },
                   targetModelPluginOptions: { i18n: { localized: true } },
                   queryInfos: {
-                    defaultParams: { test: true, _locale: 'en' },
+                    defaultParams: { test: true, locale: 'en' },
                     paramsToKeep: ['plugins.i18n.locale'],
                   },
                 },
@@ -518,7 +518,7 @@ describe('i18n | contentManagerHooks | mutateEditViewLayout', () => {
           queryInfos: {
             defaultParams: {
               test: true,
-              _locale: 'en',
+              locale: 'en',
             },
             paramsToKeep: ['plugins.i18n.locale'],
           },
diff --git a/packages/plugins/i18n/server/services/__tests__/entity-service-decorator.test.js b/packages/plugins/i18n/server/services/__tests__/entity-service-decorator.test.js
index db7aff7870..fc809381a6 100644
--- a/packages/plugins/i18n/server/services/__tests__/entity-service-decorator.test.js
+++ b/packages/plugins/i18n/server/services/__tests__/entity-service-decorator.test.js
@@ -141,7 +141,7 @@ describe('Entity service decorator', () => {
       }
     );
 
-    test('Replaces _locale param', async () => {
+    test('Replaces locale param', async () => {
       const defaultService = {
         wrapParams: jest.fn(opts => Promise.resolve(opts)),
       };
diff --git a/packages/plugins/i18n/server/services/entity-service-decorator.js b/packages/plugins/i18n/server/services/entity-service-decorator.js
index e1d0c627be..df9584a800 100644
--- a/packages/plugins/i18n/server/services/entity-service-decorator.js
+++ b/packages/plugins/i18n/server/services/entity-service-decorator.js
@@ -19,7 +19,6 @@ const paramsContain = (key, params) => {
  * @param {object} params - query params
  * @param {object} ctx
  */
-// TODO: remove _locale
 const wrapParams = async (params = {}, ctx = {}) => {
   const { action } = ctx;
 
@@ -36,20 +35,6 @@ const wrapParams = async (params = {}, ctx = {}) => {
     };
   }
 
-  // TODO: remove when the _locale is renamed to locale
-  if (has('_locale', params)) {
-    if (params['_locale'] === 'all') {
-      return omit('_locale', params);
-    }
-
-    return {
-      ...omit('_locale', params),
-      filters: {
-        $and: [{ locale: params['_locale'] }].concat(params.filters || []),
-      },
-    };
-  }
-
   const entityDefinedById = paramsContain('id', params) && SINGLE_ENTRY_ACTIONS.includes(action);
   const entitiesDefinedByIds = paramsContain('id.$in', params) && BULK_ACTIONS.includes(action);
 
diff --git a/packages/plugins/sentry/server/middlewares/sentry.js b/packages/plugins/sentry/server/middlewares/sentry.js
index a82e1d4f11..7c6c8c56d7 100644
--- a/packages/plugins/sentry/server/middlewares/sentry.js
+++ b/packages/plugins/sentry/server/middlewares/sentry.js
@@ -5,8 +5,14 @@
  * @param {{ strapi: import('@strapi/strapi').Strapi }}
  */
 module.exports = ({ strapi }) => {
-  const sentry = strapi.plugin('sentry').service('sentry');
-  sentry.init();
+  const sentryService = strapi.plugin('sentry').service('sentry');
+  sentryService.init();
+  const sentry = sentryService.getInstance();
+
+  if (!sentry) {
+    // initialization failed
+    return;
+  }
 
   strapi.server.use(async (ctx, next) => {
     try {
diff --git a/yarn.lock b/yarn.lock
index c1c2c99b64..a3b906f693 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -2881,21 +2881,6 @@
     npmlog "^4.1.2"
     write-file-atomic "^2.3.0"
 
-"@mapbox/node-pre-gyp@^1.0.0":
-  version "1.0.5"
-  resolved "https://registry.yarnpkg.com/@mapbox/node-pre-gyp/-/node-pre-gyp-1.0.5.tgz#2a0b32fcb416fb3f2250fd24cb2a81421a4f5950"
-  integrity sha512-4srsKPXWlIxp5Vbqz5uLfBN+du2fJChBoYn/f2h991WLdk7jUvcSk/McVLSv/X+xQIPI8eGD5GjrnygdyHnhPA==
-  dependencies:
-    detect-libc "^1.0.3"
-    https-proxy-agent "^5.0.0"
-    make-dir "^3.1.0"
-    node-fetch "^2.6.1"
-    nopt "^5.0.0"
-    npmlog "^4.1.2"
-    rimraf "^3.0.2"
-    semver "^7.3.4"
-    tar "^6.1.0"
-
 "@mdx-js/loader@^1.6.22":
   version "1.6.22"
   resolved "https://registry.yarnpkg.com/@mdx-js/loader/-/loader-1.6.22.tgz#d9e8fe7f8185ff13c9c8639c048b123e30d322c4"
@@ -7221,15 +7206,7 @@ bcrypt-pbkdf@^1.0.0, bcrypt-pbkdf@^1.0.2:
   dependencies:
     tweetnacl "^0.14.3"
 
-bcrypt@5.0.1:
-  version "5.0.1"
-  resolved "https://registry.yarnpkg.com/bcrypt/-/bcrypt-5.0.1.tgz#f1a2c20f208e2ccdceea4433df0c8b2c54ecdf71"
-  integrity sha512-9BTgmrhZM2t1bNuDtrtIMVSmmxZBrJ71n8Wg+YgdjHuIWYF7SjjmCPZFB+/5i/o/PIeRpwVJR3P+NrpIItUjqw==
-  dependencies:
-    "@mapbox/node-pre-gyp" "^1.0.0"
-    node-addon-api "^3.1.0"
-
-bcryptjs@^2.4.3:
+bcryptjs@2.4.3, bcryptjs@^2.4.3:
   version "2.4.3"
   resolved "https://registry.yarnpkg.com/bcryptjs/-/bcryptjs-2.4.3.tgz#9ab5627b93e60621ff7cdac5da9733027df1d0cb"
   integrity sha1-mrVie5PmBiH/fNrF2pczAn3x0Ms=
@@ -17349,13 +17326,6 @@ nopt@^4.0.1:
     abbrev "1"
     osenv "^0.1.4"
 
-nopt@^5.0.0:
-  version "5.0.0"
-  resolved "https://registry.yarnpkg.com/nopt/-/nopt-5.0.0.tgz#530942bb58a512fccafe53fe210f13a25355dc88"
-  integrity sha512-Tbj67rffqceeLpcRXrT7vKAN8CwfPeIBgM7E6iBkmKLV7bEMwpGgYLGv0jACUsECaa/vuxP0IjEont6umdMgtQ==
-  dependencies:
-    abbrev "1"
-
 normalize-package-data@^2.0.0, normalize-package-data@^2.3.0, normalize-package-data@^2.3.2, normalize-package-data@^2.3.4, normalize-package-data@^2.3.5, normalize-package-data@^2.4.0, normalize-package-data@^2.5.0:
   version "2.5.0"
   resolved "https://registry.yarnpkg.com/normalize-package-data/-/normalize-package-data-2.5.0.tgz#e66db1838b200c1dfc233225d12cb36520e234a8"