diff --git a/.github/workflows/ci.yaml b/.github/workflows/ci.yaml
index 90ded98..6011a79 100644
--- a/.github/workflows/ci.yaml
+++ b/.github/workflows/ci.yaml
@@ -32,6 +32,11 @@ jobs:
       - name: Run Go Vet
         run: go vet ./...
 
+      - name: Run golangci-lint
+        uses: golangci/golangci-lint-action@v6
+        with:
+          version: v1.59
+
       - name: Run Go Unit Tests
         run: go test -v ./...
 
diff --git a/Makefile b/Makefile
index 809f658..9fd0602 100644
--- a/Makefile
+++ b/Makefile
@@ -42,12 +42,16 @@ check:
 	@chmod +x scripts/check.sh
 	@./scripts/check.sh
 
-## lint: Run gofmt and go vet
+## lint: Run gofmt, go vet, and golangci-lint
 lint:
 	@echo "==> Verifying Go formatting..."
 	@test -z "$$(gofmt -l internal/ cmd/)" || (echo "Unformatted files:" && gofmt -l internal/ cmd/ && exit 1)
 	@echo "==> Running Go vet..."
 	@go vet ./...
+	@if command -v golangci-lint &> /dev/null; then \
+		echo "==> Running golangci-lint..."; \
+		golangci-lint run; \
+	fi
 	@echo "✓ Lint passed."
 
 ## format: Format all Go files with gofmt
diff --git a/cmd/server/main.go b/cmd/server/main.go
index 60906b4..955399c 100644
--- a/cmd/server/main.go
+++ b/cmd/server/main.go
@@ -28,7 +28,9 @@ func main() {
 	if err != nil {
 		log.Fatalf("Fatal: Database initialization failed: %v", err)
 	}
-	defer database.Close()
+	defer func() {
+		_ = database.Close()
+	}()
 	log.Printf("==> Database connected: %s (WAL mode enabled)\n", cfg.DBPath)
 
 	// 2. Initialize Auth Service & Bootstrap Admin
diff --git a/internal/api/handlers.go b/internal/api/handlers.go
index 85cc02e..6f2a430 100644
--- a/internal/api/handlers.go
+++ b/internal/api/handlers.go
@@ -345,7 +345,9 @@ func (h *Handler) ImportOPML(w http.ResponseWriter, r *http.Request) {
 		h.writeError(w, http.StatusBadRequest, "file field is required")
 		return
 	}
-	defer file.Close()
+	defer func() {
+		_ = file.Close()
+	}()
 
 	data, err := io.ReadAll(file)
 	if err != nil {
@@ -524,7 +526,3 @@ func (h *Handler) ViewSharedEntry(w http.ResponseWriter, r *http.Request) {
 	w.Header().Set("Content-Type", "text/html; charset=utf-8")
 	_, _ = w.Write([]byte(html))
 }
-
-type sqlNullHelper struct {
-	String string
-}
diff --git a/internal/api/server.go b/internal/api/server.go
index c951268..eee9610 100644
--- a/internal/api/server.go
+++ b/internal/api/server.go
@@ -16,7 +16,6 @@ func NewRouter(h *Handler, authService *auth.AuthService, staticDir string) http
 	r := chi.NewRouter()
 
 	r.Use(middleware.RequestID)
-	r.Use(middleware.RealIP)
 	r.Use(middleware.Logger)
 	r.Use(middleware.Recoverer)
 	r.Use(middleware.Compress(5))
diff --git a/internal/crawler/crawler.go b/internal/crawler/crawler.go
index 13c851f..f1ebd64 100644
--- a/internal/crawler/crawler.go
+++ b/internal/crawler/crawler.go
@@ -137,7 +137,7 @@ func (c *Crawler) runWorkerPool(ctx context.Context, feeds []models.Feed) {
 		go func() {
 			defer wg.Done()
 			for f := range jobs {
-				c.fetchSingleFeed(ctx, f)
+				_ = c.fetchSingleFeed(ctx, f)
 			}
 		}()
 	}
diff --git a/internal/db/db.go b/internal/db/db.go
index 6ed5180..1804c24 100644
--- a/internal/db/db.go
+++ b/internal/db/db.go
@@ -186,7 +186,9 @@ func (d *DB) ListCategories() ([]models.Category, error) {
 	if err != nil {
 		return nil, err
 	}
-	defer rows.Close()
+	defer func() {
+		_ = rows.Close()
+	}()
 
 	var categories []models.Category
 	for rows.Next() {
@@ -264,7 +266,9 @@ func (d *DB) ListFeeds() ([]models.Feed, error) {
 	if err != nil {
 		return nil, err
 	}
-	defer rows.Close()
+	defer func() {
+		_ = rows.Close()
+	}()
 
 	var feeds []models.Feed
 	for rows.Next() {
@@ -479,7 +483,9 @@ func (d *DB) UpsertFeedEntries(feedID string, entries []models.FeedEntry) (int,
 	if err != nil {
 		return 0, err
 	}
-	defer stmt.Close()
+	defer func() {
+		_ = stmt.Close()
+	}()
 
 	insertedCount := 0
 	for _, e := range entries {
@@ -519,9 +525,10 @@ func (d *DB) ListEntries(f EntryFilter) ([]models.FeedEntry, int, error) {
 	where := []string{"1=1"}
 	args := []interface{}{}
 
-	if f.View == "inbox" {
+	switch f.View {
+	case "inbox":
 		where = append(where, "e.is_read = 0")
-	} else if f.View == "starred" {
+	case "starred":
 		where = append(where, "e.is_starred = 1")
 	}
 
@@ -596,7 +603,9 @@ func (d *DB) ListEntries(f EntryFilter) ([]models.FeedEntry, int, error) {
 	if err != nil {
 		return nil, 0, err
 	}
-	defer rows.Close()
+	defer func() {
+		_ = rows.Close()
+	}()
 
 	var entries []models.FeedEntry
 	for rows.Next() {
diff --git a/internal/db/db_test.go b/internal/db/db_test.go
index 1e7200e..57b3dff 100644
--- a/internal/db/db_test.go
+++ b/internal/db/db_test.go
@@ -14,14 +14,18 @@ func TestDatabaseOperations(t *testing.T) {
 	if err != nil {
 		t.Fatalf("failed to create temp dir: %v", err)
 	}
-	defer os.RemoveAll(tempDir)
+	defer func() {
+		_ = os.RemoveAll(tempDir)
+	}()
 
 	dbPath := filepath.Join(tempDir, "test.db")
 	database, err := InitDB(dbPath)
 	if err != nil {
 		t.Fatalf("InitDB failed: %v", err)
 	}
-	defer database.Close()
+	defer func() {
+		_ = database.Close()
+	}()
 
 	// 1. Test User
 	u, err := database.CreateUser("admin", "$2a$10$dummyhashvalue")
diff --git a/internal/parser/parser.go b/internal/parser/parser.go
index ccb0cf4..ea19aca 100644
--- a/internal/parser/parser.go
+++ b/internal/parser/parser.go
@@ -53,7 +53,9 @@ func (p *Parser) FetchFeed(ctx context.Context, feedURL, etag, lastModified stri
 	if err != nil {
 		return nil, fmt.Errorf("failed to fetch url: %w", err)
 	}
-	defer resp.Body.Close()
+	defer func() {
+		_ = resp.Body.Close()
+	}()
 
 	if resp.StatusCode == http.StatusNotModified {
 		return &FetchResult{NotModified: true}, nil
diff --git a/scripts/check.sh b/scripts/check.sh
index 0cbd4fe..679ec2e 100755
--- a/scripts/check.sh
+++ b/scripts/check.sh
@@ -15,9 +15,14 @@ if [ -n "$UNFORMATTED" ]; then
 fi
 echo "✓ Go files formatted correctly."
 
-echo "==> 2. Running Go vet..."
+echo "==> 2. Running Go vet & golangci-lint..."
 go vet ./...
-echo "✓ Go vet passed."
+if command -v golangci-lint &> /dev/null; then
+    golangci-lint run
+    echo "✓ golangci-lint passed (0 issues)."
+else
+    echo "⚠ golangci-lint not installed locally (will run in CI)."
+fi
 
 echo "==> 3. Running Go tests..."
 go test -v ./...