diff --git a/scripts/start-dev.sh b/scripts/start-dev.sh
index 41169c4..b442162 100755
--- a/scripts/start-dev.sh
+++ b/scripts/start-dev.sh
@@ -38,6 +38,32 @@ resolve_node_toolchain() {
   command -v npm >/dev/null 2>&1
 }
 
+load_root_env() {
+  local env_file="$REPO_ROOT/.env"
+  if [ ! -f "$env_file" ]; then
+    return 0
+  fi
+  set -a
+  # shellcheck disable=SC1090
+  . "$env_file"
+  set +a
+}
+
+resolve_database_url() {
+  if [ -n "${DATABASE_URL:-}" ]; then
+    printf '%s' "$DATABASE_URL"
+    return 0
+  fi
+
+  local user="${POSTGRES_USER:-postgres}"
+  local password="${POSTGRES_PASSWORD:-}"
+  local db="${POSTGRES_DB:-daagbox}"
+  [ -z "$user" ] && user=postgres
+  [ -z "$password" ] && password=postgres
+  [ -z "$db" ] && db=daagbox
+  printf 'postgresql://%s:%s@localhost:5432/%s?schema=public' "$user" "$password" "$db"
+}
+
 check_dev_env() {
   local env_file="$REPO_ROOT/.env"
   if [ ! -f "$env_file" ]; then
@@ -91,38 +117,84 @@ echo "========================================"
 echo "Preparing to (re)start services..."
 
 require_node_toolchain
+load_root_env
+export DATABASE_URL="$(resolve_database_url)"
 check_dev_env
 
 # Clean up processes running on ports
+stop_process_tree() {
+  local pid=$1
+  [ -z "$pid" ] && return 0
+  if ! kill -0 "$pid" 2>/dev/null; then
+    return 0
+  fi
+
+  local child
+  for child in $(pgrep -P "$pid" 2>/dev/null || true); do
+    stop_process_tree "$child"
+  done
+
+  kill -TERM "$pid" 2>/dev/null || true
+}
+
+stop_process_group() {
+  local pgid=$1
+  [ -z "$pgid" ] && return 0
+  kill -TERM "-$pgid" 2>/dev/null || true
+}
+
+force_stop_process_group() {
+  local pgid=$1
+  [ -z "$pgid" ] && return 0
+  kill -KILL "-$pgid" 2>/dev/null || true
+}
+
 cleanup_port() {
   local port=$1
   if command -v lsof >/dev/null 2>&1; then
-    local pid=$(lsof -t -i:$port)
-    if [ ! -z "$pid" ]; then
-      echo "Port $port is currently in use by PID $pid. Stopping process..."
-      kill -9 $pid 2>/dev/null
+    local pids
+    pids=$(lsof -t -i:"$port" 2>/dev/null || true)
+    if [ -n "$pids" ]; then
+      echo "Port $port is currently in use. Stopping process(es)..."
+      local pid
+      for pid in $pids; do
+        stop_process_tree "$pid"
+      done
+      sleep 0.3
+      for pid in $pids; do
+        kill -KILL "$pid" 2>/dev/null || true
+      done
     fi
   elif command -v fuser >/dev/null 2>&1; then
     echo "Port $port is currently in use. Stopping process..."
-    fuser -k $port/tcp 2>/dev/null
+    fuser -k "$port"/tcp 2>/dev/null
   fi
 }
 
-cleanup_port $SERVER_PORT
-cleanup_port $CLIENT_PORT
+BACKEND_PGID=""
+CLIENT_PGID=""
 
-# Clean exit handler
 cleanup_all() {
   echo ""
   echo "Stopping all dev servers..."
-  # Kill all child jobs
-  kill $(jobs -p) 2>/dev/null
+
+  stop_process_group "$BACKEND_PGID"
+  stop_process_group "$CLIENT_PGID"
+  sleep 0.5
+  force_stop_process_group "$BACKEND_PGID"
+  force_stop_process_group "$CLIENT_PGID"
+
+  cleanup_port "$SERVER_PORT"
+  cleanup_port "$CLIENT_PORT"
   exit 0
 }
 
 # Trap termination signals
 trap cleanup_all SIGINT SIGTERM EXIT
 
+cleanup_port "$SERVER_PORT"
+cleanup_port "$CLIENT_PORT"
+
 # Manage PostgreSQL Docker container
 if command -v docker >/dev/null 2>&1; then
   echo "Checking PostgreSQL Docker container (postgres-daagbox)..."
@@ -189,8 +261,9 @@ if [ ! -d node_modules ]; then
   echo "Error: server/node_modules missing. Run: cd server && npm ci"
   exit 1
 fi
-npm run dev &
+setsid npm run dev &
 BACKEND_PID=$!
+BACKEND_PGID=$BACKEND_PID
 cd "$REPO_ROOT" || exit 1
 
 # Sleep briefly to let server start up
@@ -205,7 +278,9 @@ echo "Starting frontend dev server..."
 cd "$REPO_ROOT/client" || exit 1
 if [ ! -d node_modules ]; then
   echo "Error: client/node_modules missing. Run: cd client && npm ci"
-  kill "$BACKEND_PID" 2>/dev/null
+  stop_process_group "$BACKEND_PGID"
+  sleep 0.3
+  force_stop_process_group "$BACKEND_PGID"
   exit 1
 fi
 # Vite 6+ via plugin-react 4; refresh lockfile after package.json changes
@@ -213,14 +288,17 @@ if ! node -e "require.resolve('vite/package.json')" 2>/dev/null; then
   echo "Client dependencies incomplete — running npm ci..."
   npm ci || exit 1
 fi
-npm run dev &
+setsid npm run dev &
 CLIENT_PID=$!
+CLIENT_PGID=$CLIENT_PID
 cd "$REPO_ROOT" || exit 1
 
 sleep 1.5
 if ! kill -0 "$CLIENT_PID" 2>/dev/null; then
   echo "Error: Frontend dev server exited immediately. Check client logs above."
-  kill "$BACKEND_PID" 2>/dev/null
+  stop_process_group "$BACKEND_PGID"
+  sleep 0.3
+  force_stop_process_group "$BACKEND_PGID"
   exit 1
 fi
 
diff --git a/server/package-lock.json b/server/package-lock.json
index d884969..57468f1 100644
--- a/server/package-lock.json
+++ b/server/package-lock.json
@@ -7,6 +7,7 @@
     "": {
       "name": "server",
       "version": "1.0.0",
+      "hasInstallScript": true,
       "dependencies": {
         "@prisma/client": "^5.10.2",
         "@simplewebauthn/server": "^9.0.3",