diff --git a/.circleci/config.yml b/.circleci/config.yml
index 2ee4ce4..47f8675 100644
--- a/.circleci/config.yml
+++ b/.circleci/config.yml
@@ -1,13 +1,26 @@
+version: 2
+# --- Constants --- #
+
 globals:
   images:
     node: &node cimg/node:lts
     postgres: &postgres circleci/postgres:9.6.5
   caches:
+    dependencies: &dependencies dependencies-{{ checksum "package.json" }}
 
+# --- Commands --- #
 
+commands:
+  init:
+    description: Setup the environment
+    steps:
+      - checkout
+      - restore_cache:
+          keys:
+            - *dependencies
 
+# --- Jobs definitions --- #
 
-version: 2
 jobs:
   build: &shared-config
     docker:
@@ -17,20 +30,18 @@ jobs:
       - checkout
       - restore_cache:
           keys:
-            - dependencies-{{ checksum "package.json" }}
+            - *dependencies
             # fallback to using the latest cache if no exact match is found
             - dependencies-
       - run: yarn install
       - save_cache:
           paths:
             - node_modules
-          key: dependencies-{{ checksum "package.json" }}
+          key: *dependencies
   test:
     <<: *shared-config
     steps:
-      - checkout
-      - restore_cache:
-          key: dependencies-{{ checksum "package.json" }}
+      - init
       - run: yarn test
 
   test-e2e:
@@ -43,16 +54,25 @@ jobs:
           POSTGRES_USER: postgres
           POSTGRES_PASSWORD: postgres
     steps:
-      - checkout
-      - restore_cache:
-          keys:
-            - dependencies-{{ checksum "package.json" }}
+      - init
       - run:
           command: yarn test:e2e
           environment:
             DATABASE_URL: postgres://postgres:postgres@localhost:5432/postgres
 
+  lint:
+    <<: *shared-config
+    steps:
+      - init
+      - run:
+          name: Check files format
+          command: yarn format:check
 
+      - run:
+          name: Lint files
+          command: yarn lint
+
+# --- Workflow definition --- #
 
 workflows:
   version: 2
@@ -65,3 +85,6 @@ workflows:
       - test-e2e:
           requires:
             - build
+      - lint:
+          requires:
+            - build