diff --git a/scripts/dev.sh b/scripts/dev.sh
new file mode 100755
index 0000000..5b76cab
--- /dev/null
+++ b/scripts/dev.sh
@@ -0,0 +1,47 @@
+#!/usr/bin/env bash
+# Local bring-up for ecomm (SD-0001 PUC-10). From a clean checkout this:
+#   1. starts the dev Postgres container and waits for it to be healthy (owns its
+#      lifecycle — Docker is the one prerequisite, docs/BOOTSTRAP.md);
+#   2. ensures the backend venv + deps and the frontend node_modules;
+#   3. runs the FastAPI backend (:8000, self-migrating an empty DB) and the Vite dev
+#      server (:5173, proxying /api -> :8000) together.
+# Ctrl-C stops both processes; the container keeps running (stop it with
+# `docker compose down`, or `docker compose down -v` to reset to empty).
+set -euo pipefail
+
+repo_root="$(cd "$(dirname "${BASH_SOURCE[0]}")/.." && pwd)"
+cd "$repo_root"
+
+export ECOMM_DATABASE_URL="${ECOMM_DATABASE_URL:-postgresql://ecomm:ecomm@localhost:5432/ecomm}"
+
+echo "==> dev Postgres (docker compose up --wait)"
+docker compose up -d --wait db
+
+if [ ! -x "$repo_root/.venv/bin/python" ]; then
+  echo "==> creating backend venv"
+  python3 -m venv "$repo_root/.venv"
+  "$repo_root/.venv/bin/python" -m pip install --upgrade pip
+  "$repo_root/.venv/bin/python" -m pip install -r "$repo_root/backend/requirements.txt"
+fi
+
+if [ ! -d "$repo_root/frontend/node_modules" ]; then
+  echo "==> installing frontend deps"
+  ( cd "$repo_root/frontend" && npm install )
+fi
+
+echo "==> starting backend (:8000) and Vite (:5173) — Ctrl-C to stop"
+"$repo_root/.venv/bin/python" -m uvicorn app.main:app --app-dir "$repo_root/backend" --port 8000 --reload &
+backend_pid=$!
+( cd "$repo_root/frontend" && npm run dev ) &
+frontend_pid=$!
+
+cleanup() {
+  echo
+  echo "==> stopping backend and Vite"
+  kill "$backend_pid" "$frontend_pid" 2>/dev/null || true
+  wait "$backend_pid" "$frontend_pid" 2>/dev/null || true
+}
+trap cleanup INT TERM
+
+wait -n "$backend_pid" "$frontend_pid"
+cleanup