Flipkart Machine coding round

Interview question for Machine coding round for Flipkart

**Flipkart Minutes – Quick Commerce System **

Description

Implement the core system for Flipkart Minutes, Flipkart’s instant delivery platform, enabling customers to order any item for delivery within minutes. The system should efficiently manage customers, delivery partners, and orders, ensuring rapid and reliable fulfillment.

**Core Requirements **

1. Onboarding ● The system should support onboarding of new customers and delivery partners.

2. Order Placement & Cancellation ● Customers can place orders for any item (item name or ID is specified in the order). ● There are no in-stock/out-of-stock constraints; all items are always available. ● Customers can cancel orders if they have not yet been picked up by a delivery partner.

3. Order Assignment & Fulfillment ● Orders are auto-assigned to any available delivery partner. ● If no delivery partner is available, the order remains in a queue and is assigned as soon as a partner becomes free. ● Each delivery partner can handle only one order at a time. ● The number of ongoing orders can exceed the number of delivery partners (orders may queue). ● Delivery partners can pick up assigned orders and mark them as delivered. ● Canceled orders should not be assigned to a delivery partner ● If an assigned order gets canceled before pickup, the delivery partner should become available for other orders ● Once a delivery partner picks up an order, the order cannot be canceled by the customer or the system. ● Assume delivery partners are available 24x7. Ignore travel time.

4. Status Tracking ● The system should provide real-time status for orders and delivery partners.

5. Concurrency & Thread Safety ● The system must be thread-safe and handle all concurrency scenarios (multiple customers and partners acting simultaneously).

Bonus Features ● Notifications: Notify customers and delivery partners (via simulated logs) on order status changes. ● Ratings: Customers can rate delivery partners after successful delivery. ● Dashboard: Show top delivery partners based on number of deliveries and ratings. ● Auto-cancel: If no delivery partner picks up the order within 30 minutes of its creation, the order should be canceled automatically regardless of whether an order has been assigned to a delivery partner or not

**Guidelines: ** ● Time: 120 mins (Implementation). ● Write modular, clean and demo-able code (Test cases or runtime execution). ● A driver program/main class/test case is needed to test out the code by the evaluator with multiple test cases. ● Use design patterns wherever applicable. ● Please handle concurrency wherever applicable. ● Evaluation criteria: Demoable & functionally correct code, Code readability, Proper Entity modeling, Modularity & Extensibility, Separation of concerns, Abstractions, Exception Handling, Code comments. ● Code should handle edge cases properly and fail gracefully. ● You are not allowed to use any external databases like MySQL. Use only in-memory data structures. ● No need to create any UX or any HTTP API. It should be a standalone application. ● Usage of any AI powered tools such a chatGPT or github-copilot is strictly prohibited. You may use the internet to look up any syntactic references. ● You are free to use any popular programming language of your choice. ● The bonus features are optional. Attempt them only after finishing the p0 features. ● The problem may require you to make certain assumptions. Do make reasonable assumptions and convey them to the review panel.

Sample Test cases: The input/output need not be in the same format this is for explaining the expected functionality i: input o: output ● onboard customer - customer_id, name ● onboard delivery_partner - partner_id, name ● create order - customer_id, item_name ● cancel order - order_id ● show order status - (order_id) ● show delivery partner status - (partner_id) ● pick up order - (partner_id, order_id) ● complete order - (partner_id, order_id)