backend-task-data
Shipped: Library loans
Built a FastAPI/SQLite library-loans API with four related tables and 11,000 seeded loan records. The README includes before/after query plans and benchmarks showing the endpoint runs under 200 ms. Database constraints prevent double lending, and automated tests verify all requirements. Repository: https://github.com/quratulain-nayeem/library-loans-api Built for the Verified Backend Internship · a data model and the queries on it
Shipped: Library loans
Repository: https://sgm322.github.io/LibraryLoansAPi/ Built for the Verified Backend Internship · a data model and the queries on it
Shipped: Ticket sales
Built a concurrency-safe Ticket Booking REST API using Node.js and MySQL (InnoDB) meeting all Brief B criteria: 1. Data Model & Integrity: Normalized schema with events, seats, and orders using foreign keys, CASCADE constraints, and a UNIQUE constraint on seat reservations. 2. High-Volume Inventory: Seeded 10,000+ seat records across 5 events via an automated stored procedure. 3. Sub-200ms Latency: Implemented composite index idx event reserved on (event id, is reserved); GET /events/:id/free-seats fetches 2,000 available seats in under 25 ms. 4. Concurrency & Race Condition Safe: Applied pessimistic row locking (SELECT ... FOR UPDATE) inside database transactions. Verified via parallel PowerShell background jobs showing one request succeeding (201 Created) while simultaneous conflicting attempts fail (409 Conflict). Full schema, setup commands, and execution proofs are documented in the repository README.md. Repository: https://github.com/roh155/ticket booking Built for the Verified Backend Internship · a data model and the queries on it
Shipped: Ticket sales
What Was Built A ticket reservation API with three endpoints: 1. GET /events — lists all events 2. GET /events/:eventId/seats/free — lists free seats for an event (27,040 seats for event 1) 3. POST /seats/:seatId/reserve — reserves a seat with race-condition protection Acceptance Criteria — How to Verify 1. Three or more related tables with foreign keys node -e "const db = require('./db'); console.log(db.prepare(\"SELECT sql FROM sqlite master WHERE type='table'\").all().map(r = r.sql).join('\n\n'))" Shows events, seats (FK to events), and orders (FK to seats) with constraints. 2. At least 10,000 seeded rows npm run seed node -e "const db = require('./db'); console.log('Seats:', db.prepare('SELECT COUNT( ) as c FROM seats').get().c)" Outputs Seats: 135200. 3. Listing free seats responds in under 200ms npm start node race-test.js or time the endpoint Response time: 20ms for 27,040 seats. 4. Two concurrent reservations cannot both succeed node race-test.js Outputs: Request 1 (Alice): Status 201 Request 2 (Bob): Status 409 SUCCESS: Only one reservation went through 5. README shows query plan before and after index node queryplan.js Outputs: - Before: SEARCH s USING INDEX sqlite autoindex seats 1 (event id=?) - After: SEARCH s USING COVERING INDEX idx seats event status (event id=? AND status=?) Repository: https://github.com/techtuber9988/ticket-sales Built for the Verified Backend Internship · a data model and the queries on it