diff --git a/orders-backend/src/main/java/com/andwati/orders/repository/InventoryItemRepository.java b/orders-backend/src/main/java/com/andwati/orders/repository/InventoryItemRepository.java
new file mode 100644
index 0000000..19fc29a
--- /dev/null
+++ b/orders-backend/src/main/java/com/andwati/orders/repository/InventoryItemRepository.java
@@ -0,0 +1,46 @@
+package com.andwati.orders.repository;
+
+import com.andwati.orders.model.InventoryItem;
+import jakarta.persistence.LockModeType;
+import org.springframework.data.jpa.repository.JpaRepository;
+import org.springframework.data.jpa.repository.Lock;
+import org.springframework.data.jpa.repository.Query;
+import org.springframework.data.repository.query.Param;
+
+import java.util.Collection;
+import java.util.List;
+import java.util.Optional;
+import java.util.UUID;
+
+public interface InventoryItemRepository extends JpaRepository<InventoryItem, UUID> {
+
+    @Query("""
+            select inventory
+            from InventoryItem inventory
+            join fetch inventory.product product
+            order by product.name asc
+            """)
+    List<InventoryItem> findAllWithProducts();
+
+    @Query("""
+            select inventory
+            from InventoryItem inventory
+            join fetch inventory.product product
+            where inventory.availableQuantity < :threshold
+            order by inventory.availableQuantity asc, product.name asc
+            """)
+    List<InventoryItem> findLowStockItems(@Param("threshold") int threshold);
+
+    Optional<InventoryItem> findByProduct_Id(UUID productId);
+
+    List<InventoryItem> findByProduct_IdIn(Collection<UUID> productIds);
+
+    @Lock(LockModeType.PESSIMISTIC_WRITE)
+    @Query("""
+            select inventory
+            from InventoryItem inventory
+            join fetch inventory.product product
+            where product.id in :productIds
+            """)
+    List<InventoryItem> findByProductIdsForUpdate(@Param("productIds") Collection<UUID> productIds);
+}
\ No newline at end of file
diff --git a/orders-backend/src/main/java/com/andwati/orders/repository/OrderItemRepository.java b/orders-backend/src/main/java/com/andwati/orders/repository/OrderItemRepository.java
new file mode 100644
index 0000000..a40330f
--- /dev/null
+++ b/orders-backend/src/main/java/com/andwati/orders/repository/OrderItemRepository.java
@@ -0,0 +1,9 @@
+package com.andwati.orders.repository;
+
+import com.andwati.orders.model.OrderItem;
+import org.springframework.data.jpa.repository.JpaRepository;
+
+import java.util.UUID;
+
+public interface OrderItemRepository extends JpaRepository<OrderItem, UUID> {
+}
\ No newline at end of file
diff --git a/orders-backend/src/main/java/com/andwati/orders/repository/OrderRepository.java b/orders-backend/src/main/java/com/andwati/orders/repository/OrderRepository.java
new file mode 100644
index 0000000..6ed51b0
--- /dev/null
+++ b/orders-backend/src/main/java/com/andwati/orders/repository/OrderRepository.java
@@ -0,0 +1,15 @@
+package com.andwati.orders.repository;
+
+import com.andwati.orders.model.Order;
+import org.springframework.data.jpa.repository.EntityGraph;
+import org.springframework.data.jpa.repository.JpaRepository;
+import org.springframework.data.jpa.repository.JpaSpecificationExecutor;
+
+import java.util.Optional;
+import java.util.UUID;
+
+public interface OrderRepository extends JpaRepository<Order, UUID>, JpaSpecificationExecutor<Order> {
+
+    @EntityGraph(attributePaths = {"items", "items.product"})
+    Optional<Order> findWithItemsById(UUID id);
+}
\ No newline at end of file
diff --git a/orders-backend/src/main/java/com/andwati/orders/repository/ProductRepository.java b/orders-backend/src/main/java/com/andwati/orders/repository/ProductRepository.java
new file mode 100644
index 0000000..25ff8cd
--- /dev/null
+++ b/orders-backend/src/main/java/com/andwati/orders/repository/ProductRepository.java
@@ -0,0 +1,13 @@
+package com.andwati.orders.repository;
+
+import com.andwati.orders.model.Product;
+import org.springframework.data.jpa.repository.JpaRepository;
+
+import java.util.Collection;
+import java.util.List;
+import java.util.UUID;
+
+public interface ProductRepository extends JpaRepository<Product, UUID> {
+
+    List<Product> findByIdIn(Collection<UUID> ids);
+}
\ No newline at end of file