Problems

Each problem is a small multi-file project with seeded bugs (or a missing feature), visible tests and hidden tests. Pick one, fix it, and submit. Problems marked Sign in need a free account.

• 01

  01Returns Eligibility Service

  Return-policy rule engine + JSON parser

  C++MediumBug fix60 min
• 02

  02Last-Mile Slot Scheduler

  Delivery slot scheduler (key=value manifests)

  C++EasyBug fix60 min
• 03

  03Fulfillment Inventory Reservation API

  Inventory reservation REST API (CSV stock load)

  Java · Spring BootEasyBug fix60 min
• 04

  04Marketplace Seller Payouts API

  Seller payout ledger REST API (CSV import, fees, auth)

  Java · Spring BootMediumBug fix60 min
• 05

  05Pickup Locker Network

  Pickup locker network (implement assign)

  C++MediumFeature60 min
• 06

  06Parcel Shipping Cost Calculator

  Parcel shipping cost calculator (rate card, volumetric weight)

  C++EasyBug fix60 min

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• 07

  07Service Latency Log Analyzer

  Service latency log analyzer (percentiles, error rates)

  C++MediumBug fix60 min

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• 08

  08Checkout Coupon Service

  Checkout coupon REST API (quote, redeem, limits)

  Java · Spring BootEasyBug fix60 min

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• 09

  09Order Lifecycle Service

  Order lifecycle REST API (state machine, ownership, cart parsing)

  Java · Spring BootMediumBug fix60 min

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• 10

  10Cart Promotion Pricing Engine

  Cart promotion pricing engine (implement price)

  Java · Spring BootMediumFeature60 min

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