diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index 68d8c2036732822feb0a083fc8b3f040e81ff128..10c9bb5631d418aedb4c000084dfafef9d6fc5a9 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -1,9 +1,8 @@
 # In CI we use the latest docker images.
 
 stages:
-  - check
+  - check_and_lint
   - test
-  - lint
   - svg-gen-docu # required to be done before documentation and in separate stages
   - documentation
 
@@ -15,7 +14,7 @@ stages:
 
 check_back:
   <<: *only-default
-  stage: check
+  stage: check_and_lint
   image: registry.gitlab.utc.fr/rex-dri/rex-dri/backend:v0.2.1
   before_script:
     - sh ./backend/init_logs.sh
@@ -35,7 +34,7 @@ check_back:
 
 check_front:
   <<: *only-default
-  stage: check
+  stage: check_and_lint
   image: registry.gitlab.utc.fr/rex-dri/rex-dri/frontend:v2.1.0
   before_script:
     - cd frontend && mkdir -p node_modules && mv -f /usr/src/deps/node_modules/* /usr/src/deps/node_modules/.bin ./node_modules/
@@ -48,6 +47,29 @@ check_front:
   tags:
     - docker
 
+lint_backend:
+  <<: *only-default
+  stage: check_and_lint
+  image: registry.gitlab.utc.fr/rex-dri/rex-dri/backend:v0.2.1
+  script:
+    - cd backend
+    - black --check . 
+    - flake8
+  tags:
+    - docker
+
+lint_frontend_and_documentation:
+  <<: *only-default
+  stage: check_and_lint
+  image: registry.gitlab.utc.fr/rex-dri/rex-dri/frontend:v2.1.0
+  before_script:
+    - cd frontend && mkdir -p node_modules && mv -f /usr/src/deps/node_modules/* /usr/src/deps/node_modules/.bin ./node_modules/
+  script:
+    - yarn lint
+    - yarn lint-doc
+  tags:
+    - docker
+
 test_back:
   <<: *only-default
   stage: test
@@ -86,26 +108,6 @@ test_frontend:
   tags:
     - docker
 
-flake8:
-  <<: *only-default
-  stage: lint
-  image: registry.gitlab.utc.fr/rex-dri/rex-dri/backend:v0.2.1
-  script:
-    - cd backend && flake8
-  tags:
-    - docker
-
-eslint:
-  <<: *only-default
-  stage: lint
-  image: registry.gitlab.utc.fr/rex-dri/rex-dri/frontend:v2.1.0
-  before_script:
-    - cd frontend && mkdir -p node_modules && mv -f /usr/src/deps/node_modules/* /usr/src/deps/node_modules/.bin ./node_modules/
-  script:
-    - yarn lint
-  tags:
-    - docker
-
 generate_UML_svg:
   <<: *only-default
   stage: svg-gen-docu
diff --git a/CHANGELOG.md b/CHANGELOG.md
index affba45590254c16835ed983f4b72c44c9208b43..d3693969b9a5995f1996968316721f32d4e0d5f1 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -2,6 +2,8 @@
 
 ## Next
 
+- [feat] ci: run black and prettier in ci 
+
 ###### _TBD_
 
 - [chore] front: updated wording and information regarding previous exchanges and offers
diff --git a/Makefile b/Makefile
index 73b679ce5c0c99d101a872c9af08dea1897f88e8..04810b1eb3d6d1435fad60b5795362cde22d73ba 100644
--- a/Makefile
+++ b/Makefile
@@ -27,6 +27,12 @@ docker-pull:
 reformat_backend:
 	docker-compose exec backend sh -c "cd backend && black ."
 
+reformat_frontend:
+	docker-compose exec frontend sh -c "cd frontend && yarn reformat"
+
+reformat_documentation:
+	docker-compose exec frontend sh -c "cd frontend && yarn reformat-doc"
+
 test_backend:
 	docker-compose exec backend sh -c "cd backend && pytest --cov --cov-config .coveragerc --cov-report term base_app/ backend_app/ stats_app/"
 
@@ -37,11 +43,14 @@ check_backend:
 	docker-compose exec backend sh -c "cd backend && ./manage.py check"
 
 lint_backend:
-	docker-compose exec backend sh -c "cd backend && flake8"
+	docker-compose exec backend sh -c "cd backend && black --check . && flake8"
 
 lint_frontend:
 	docker-compose exec frontend sh -c "cd frontend && yarn lint"
 
+lint_documentation:
+	docker-compose exec frontend sh -c "cd frontend && yarn lint-doc"
+
 build_frontend:
 	docker-compose exec frontend sh -c "cd frontend && yarn build"
 
diff --git a/backend/base_app/views.py b/backend/base_app/views.py
index 50e6642c4060a53bf385a21586e9838b49f86d70..bad53215fa4c3ff5e9b8c8afe6b5c482feec8bfe 100644
--- a/backend/base_app/views.py
+++ b/backend/base_app/views.py
@@ -60,14 +60,10 @@ def stats(request):
 
     if dataset == "daily_connections":
         daily_connections = DailyConnections.objects.filter(
-            date__gte=now_minus_365_days,
-            date__lt=now,
+            date__gte=now_minus_365_days, date__lt=now
         )
         raw_data = [
-            {
-                "date": dc.date.strftime("%Y-%m-%d"),
-                "nb_connections": dc.nb_connections
-            }
+            {"date": dc.date.strftime("%Y-%m-%d"), "nb_connections": dc.nb_connections}
             for dc in daily_connections
         ]
 
@@ -75,8 +71,7 @@ def stats(request):
 
     elif dataset == "daily_exchange_contributions":
         daily_contributions = DailyExchangeContributionsInfo.objects.filter(
-            date__gte=now_minus_365_days,
-            date__lt=now,
+            date__gte=now_minus_365_days, date__lt=now
         ).prefetch_related("university")
 
         raw_data = [
diff --git a/documentation/ProdRelated/maintenance/update_major_minor.md b/documentation/ProdRelated/maintenance/update_major_minor.md
index 1f0040e078dd9b6e931996e513cbacb17dcc5a20..c5a4f1dbbf89974e1455a0571c4243da3a403160 100644
--- a/documentation/ProdRelated/maintenance/update_major_minor.md
+++ b/documentation/ProdRelated/maintenance/update_major_minor.md
@@ -6,12 +6,12 @@ In `frontend/src/utils/majorMinorMappings.js`, each change has to be added as a
 
 ```js
 export const majorMapping = {
-  oldMajorName: "newMajorName"
+  oldMajorName: "newMajorName",
 };
 
 export const minorMapping = {
   majorName: {
-    oldMinorName: "newMinorName"
-  }
+    oldMinorName: "newMinorName",
+  },
 };
 ```
diff --git a/frontend/.prettierignore b/frontend/.prettierignore
new file mode 100644
index 0000000000000000000000000000000000000000..b7a13d98004a152f5970e9d21877e7751bf2a386
--- /dev/null
+++ b/frontend/.prettierignore
@@ -0,0 +1 @@
+/webpack-stats.json
diff --git a/frontend/package.json b/frontend/package.json
index 7d8494e09463220a50b4c5645a5debc759e65fa0..ce365f3cc67727356df17ccf0344c275fc740e50 100644
--- a/frontend/package.json
+++ b/frontend/package.json
@@ -4,8 +4,11 @@
   "description": "[![build](/../badges/master/build.svg)](https://gitlab.utc.fr/chehabfl/outgoing_rex/pipelines) [![coverage](/../badges/master/coverage.svg)](https://chehabfl.gitlab.utc.fr/outgoing_rex/) [![License](https://img.shields.io/badge/License-BSD%202--Clause-green.svg)](https://opensource.org/licenses/BSD-2-Clause)",
   "main": "manage.py",
   "scripts": {
-    "lint": "eslint src --ext js --ext jsx",
+    "lint": "prettier --check . && eslint src --ext js --ext jsx",
+    "reformat": "prettier --write .",
     "lint-fix": "eslint src --ext js --ext jsx --fix",
+    "lint-doc": "prettier --check ../documentation",
+    "reformat-doc": "prettier --write ../documentation",
     "dev": "node server.js",
     "build": "webpack --config webpack.config.build.js",
     "test": "jest",