diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 8b7f0e2f..9add9751 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -2,7 +2,11 @@ name: CI
 
 on:
   push:
-    branches: [ "main", "dev" ]
+    branches:
+        - main
+        - dev
+        - "feat/**"
+        - "fix/**"
   pull_request:
     branches: [ "main", "dev" ]
 
@@ -12,8 +16,46 @@ env:
   DATABASE_URL: "postgres://postgres:postgres@localhost/oxicloud_test"
 
 jobs:
-  fmt:
+
+  # Detect which parts of the codebase changed
+  changes:
+    runs-on: ubuntu-latest
+    outputs:
+      frontend: ${{ steps.filter.outputs.frontend }}
+      backend: ${{ steps.filter.outputs.backend }}
+    steps:
+      - uses: actions/checkout@v4
+      - uses: dorny/paths-filter@v3
+        id: filter
+        with:
+          filters: |
+            frontend:
+              - 'static/**'
+              - 'biome.json'
+              - 'jsconfig.json'
+            backend:
+              - 'src/**'
+              - 'Cargo.toml'
+              - 'Cargo.lock'
+
+  frontend-linter:
+    name: Frontend — Biome
+    needs: changes
+    if: needs.changes.outputs.frontend == 'true'
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+
+      - name: Install Biome
+        uses: biomejs/setup-biome@v2
+
+      - name: Run Biome check
+        run: biome ci static/
+
+  rust-fmt:
     name: Rustfmt
+    needs: changes
+    if: needs.changes.outputs.backend == 'true'
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v6
@@ -22,8 +64,10 @@ jobs:
           components: rustfmt
       - run: cargo fmt --all --check
 
-  clippy:
+  rust-clippy:
     name: Clippy
+    needs: changes
+    if: needs.changes.outputs.backend == 'true'
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v6
@@ -33,8 +77,10 @@ jobs:
       - uses: Swatinem/rust-cache@v2
       - run: cargo clippy --all-targets --all-features -- -D warnings
 
-  test:
+  rust-test:
     name: Tests
+    needs: changes
+    if: needs.changes.outputs.backend == 'true'
     runs-on: ubuntu-latest
     services:
       postgres:
@@ -65,8 +111,10 @@ jobs:
         env:
           DATABASE_URL: "postgres://postgres:postgres@localhost/oxicloud_test"
 
-  audit:
+  rust-audit:
     name: Security Audit
+    needs: changes
+    if: needs.changes.outputs.backend == 'true'
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v6
@@ -81,7 +129,7 @@ jobs:
   build:
     name: Build Check
     runs-on: ubuntu-latest
-    needs: [fmt, clippy, test]
+    needs: [frontend-linter, rust-fmt, rust-clippy, rust-test]
     steps:
       - uses: actions/checkout@v6
       - uses: dtolnay/rust-toolchain@stable
diff --git a/README.md b/README.md
index f11b9a00..c0231010 100644
--- a/README.md
+++ b/README.md
@@ -214,6 +214,8 @@ Full reference: [`example.env`](example.env) · [Deployment guide](doc/deploymen
 
 ## Development
 
+### Server side
+
 ```bash
 cargo build                 # Dev build
 cargo run                   # Run locally
@@ -223,6 +225,16 @@ cargo fmt --all --check     # Format check
 RUST_LOG=debug cargo run    # Debug logging
 ```
 
+### Client side
+
+Run server in dev profile:
+
+```bash
+PROFILE=dev cargo run
+```
+
+CSS & JS linter is `biome` (can be installed via `cargo install biome-cli` or on MacOS: `brew install biome`)
+
 ### Project stats
 
 | Metric | Value |
diff --git a/biome.json b/biome.json
new file mode 100644
index 00000000..56b68bf9
--- /dev/null
+++ b/biome.json
@@ -0,0 +1,42 @@
+{
+  "files": {
+    "includes": ["static/**/*.js", "static/**/*.css", "static/**/*.json" ]
+  },
+  "formatter": {
+    "enabled": true,
+    "indentStyle": "space",
+    "indentWidth": 4,
+    "lineWidth": 160,
+    "lineEnding": "lf"
+  },
+  "linter": {
+    "enabled": true,
+    "rules": {
+      "recommended": true,
+      "correctness": {
+        "noUnusedVariables": "warn"
+      }
+    }
+  },
+  "javascript": {
+    "formatter": {
+      "indentStyle": "space",
+      "indentWidth": 4,
+      "quoteStyle": "single",
+      "semicolons": "always",
+      "trailingCommas": "none",
+      "bracketSameLine": false,
+      "bracketSpacing": true,
+      "operatorLinebreak": "after"
+
+    }
+  },
+  "css": {
+    "linter": {
+      "enabled": true
+    },
+    "formatter": {
+      "enabled": true
+    }
+  }
+}
diff --git a/jsconfig.json b/jsconfig.json
new file mode 100644
index 00000000..f09567bd
--- /dev/null
+++ b/jsconfig.json
@@ -0,0 +1,18 @@
+{
+  "compilerOptions": {
+    // Enable type checking on all JS files (equivalent to @ts-check globally)
+    "checkJs": true,
+    "strict": true,
+    "noImplicitAny": true,
+    "noImplicitReturns": true,
+    "noUnusedLocals": true,
+    "noUnusedParameters": true,
+    "exactOptionalPropertyTypes": true,
+    "target": "ES2022",
+    "lib": ["ES2022", "DOM"],
+    // Treat all JS files as modules
+    "moduleDetection": "force"
+  },
+  "include": ["static/js/**/*.js"],
+  "exclude": []
+}