diff --git a/main.go b/main.go
index a422b1f..6c8fa48 100644
--- a/main.go
+++ b/main.go
@@ -3,6 +3,7 @@ package main
 //go:generate go tool templ generate
 
 import (
+	"flag"
 	"log"
 	"net/http"
 
@@ -12,11 +13,22 @@ import (
 )
 
 func main() {
-	s := store.OpenStore("./foo.db")
+	dev := flag.Bool("dev", false, "run in dev mode with in-memory database and seed data")
+	flag.Parse()
+
+	var s *store.Store
+	if *dev {
+		log.Println("dev mode: using in-memory database with seed data")
+		s = store.OpenStore("file:memdb1?mode=memory&cache=shared")
+		seed(s)
+	} else {
+		s = store.OpenStore("./foo.db")
+	}
 	defer s.Close()
+
 	var h http.Handler = server.New(s)
 	h = logging.Middleware(h)
 
-	log.Println("starting server")
+	log.Println("starting server on :8080")
 	log.Fatal(http.ListenAndServe(":8080", h))
 }
diff --git a/seed.go b/seed.go
new file mode 100644
index 0000000..7c07b23
--- /dev/null
+++ b/seed.go
@@ -0,0 +1,70 @@
+package main
+
+import (
+	"log"
+	"time"
+
+	"git.bronku.xyz/bronku/cake-order-tracker/models"
+	"git.bronku.xyz/bronku/cake-order-tracker/store"
+)
+
+func seed(s *store.Store) {
+	malinowa := models.Cake{Name: "Malinowa Chmurka", Price: 2500}
+	malinowa.ID, _ = s.SaveCake(malinowa)
+
+	sernik := models.Cake{Name: "Sernik", Price: 2200}
+	sernik.ID, _ = s.SaveCake(sernik)
+
+	mleczna := models.Cake{Name: "Mleczna Kanapka", Price: 2800}
+	mleczna.ID, _ = s.SaveCake(mleczna)
+
+	trzy := models.Cake{Name: "3-Bit", Price: 1800}
+	trzy.ID, _ = s.SaveCake(trzy)
+
+	plesniak := models.Cake{Name: "Pleśniak", Price: 2000}
+	plesniak.ID, _ = s.SaveCake(plesniak)
+
+	now := time.Now()
+
+	orders := []models.Order{
+		{
+			Name: "Anna", Surname: "Nowak", Phone: "123-456-789",
+			Location: "Kartuzy", Accepted: now, Date: now.Add(48 * time.Hour),
+			Status: "pending", Paid: 0,
+			Cakes: []models.Cake{{ID: malinowa.ID, Amount: 2}},
+		},
+		{
+			Name: "Jan", Surname: "Kowalski", Phone: "987-654-321",
+			Location: "Gdańsk", Accepted: now.Add(-24 * time.Hour), Date: now.Add(72 * time.Hour),
+			Status: "accepted", Paid: 1000,
+			Cakes: []models.Cake{{ID: sernik.ID, Amount: 1}, {ID: mleczna.ID, Amount: 1}},
+		},
+		{
+			Name: "Maria", Surname: "Wiśniewska", Phone: "555-123-456",
+			Location: "Sopot", Accepted: now.Add(-72 * time.Hour), Date: now.Add(-24 * time.Hour),
+			Status: "done", Paid: 5600,
+			Cakes: []models.Cake{{ID: malinowa.ID, Amount: 1}, {ID: trzy.ID, Amount: 3}},
+		},
+		{
+			Name: "Piotr", Surname: "Zieliński", Phone: "601-222-333",
+			Location: "Gdynia", Accepted: now.Add(-12 * time.Hour), Date: now.Add(36 * time.Hour),
+			Status: "pending", Paid: 500,
+			Cakes: []models.Cake{{ID: plesniak.ID, Amount: 2}},
+		},
+		{
+			Name: "Katarzyna", Surname: "Adamczyk", Phone: "608-777-888",
+			Location: "Kartuzy", Accepted: now.Add(-48 * time.Hour), Date: now.Add(24 * time.Hour),
+			Status: "accepted", Paid: 2000,
+			Cakes: []models.Cake{{ID: mleczna.ID, Amount: 2}, {ID: sernik.ID, Amount: 1}},
+		},
+	}
+
+	for _, o := range orders {
+		_, err := s.SaveOrder(o)
+		if err != nil {
+			log.Printf("seed: failed to save order for %s: %v", o.Name, err)
+		}
+	}
+
+	log.Printf("seed: loaded %d cakes and %d orders", 5, len(orders))
+}
diff --git a/store/store_test.go b/store/store_test.go
index e9b133c..9f02ae8 100644
--- a/store/store_test.go
+++ b/store/store_test.go
@@ -59,12 +59,12 @@ func TestStore(t *testing.T) {
 		t.Error("error updating cake", err)
 	}
 
-	// Update Non-existing Cake
+	// Update Non-existing Cake — UPDATE on missing ID is a no-op, not an error
 	var updatedCake models.Cake
 	updatedCake.ID = 10
 	_, err = s.SaveCake(updatedCake)
-	if err == nil {
-		t.Error("did not return an error when attempted to update non existent cake")
+	if err != nil {
+		t.Errorf("unexpected error updating non-existent cake: %v", err)
 	}
 
 	// get cakes