diff --git a/Makefile b/Makefile
index 33b6dcc1..00063a86 100644
--- a/Makefile
+++ b/Makefile
@@ -1,4 +1,4 @@
-.PHONY: build build-backend build-estimator build-dbt
+.PHONY: build build-backend build-estimator build-dbt deploy-frontend
 
 build: build-backend build-estimator build-dbt
 
@@ -10,3 +10,13 @@ build-estimator:
 
 build-dbt:
 	docker build -t atcoder-problems-2025-dbt:latest ./dbt
+
+FRONTEND_DIR := atcoder-problems-frontend
+S3_BUCKET ?= kenkoooo.com
+
+# Build the frontend locally and sync the artifacts to S3.
+# Note: --delete is intentionally NOT used because the destination bucket also
+# hosts backend-generated data (e.g. resources/) that is not part of the build.
+deploy-frontend:
+	cd $(FRONTEND_DIR) && pnpm install --frozen-lockfile && pnpm run build
+	aws s3 sync $(FRONTEND_DIR)/build/ s3://$(S3_BUCKET)/