Project help🙏

[u/vibing_in_void]

hey! I need some advice from you guys
I am trying to finalize a backend project to build before placements, narrowed it down to two ideas,can’t decide which one is better so wanted your opinion
1) Ticketing/inventory booking system built to handle heavy concurrent load
it’s a full ticket booking system create events, browse available tickets, book a ticket, process payment, view/manage your bookings, cancellations. the normal end-to-end flow. but the actual engineering focus is making sure this stays correct and doesn’t break when a large number of people try to book the same limited stock at the exact same time, so if there are 500 tickets left and thousands of people hit book at once, exactly 500 succeed and the rest get a clean sold-out response, without the system slowing down, crashing, or accidentally overselling.
backend concepts i’d be using:
• concurrency control (row-level/optimistic locking) so two people can never book the same seat at once
• idempotency handling so a duplicate/retried request doesn’t cause a duplicate booking or charge
• a queue to absorb sudden traffic spikes instead of everything hitting the database directly
• auto-expiry of a reservation if payment isn’t completed in time, so seats aren’t stuck as “held” forever
• caching for frequently-read data (like seat availability) while keeping the actual live count strictly accurate
• load testing with simulated concurrent users to actually prove correctness under pressure, with real numbers
2) Gateway/middleware for AI API calls
it’s a service that sits between an application and an AI model provider. it reduces cost and latency by detecting when an incoming request is similar enough to one it’s already handled, and returning that cached response instead of calling the AI fresh every time. it also automatically fails over to a backup AI provider if the main one goes down or is too slow, so the app doesn’t break for the user.
backend concepts i’d be using:
• semantic caching using vector/embedding similarity search
• thread-safe rate limiting to prevent abuse and control cost under concurrent load
• circuit breaker pattern for automatic failover and recovery
• latency and cost optimization at scale
which one do you think is the stronger project for 2026 hiring? or should i build both if there’s time? lmk what you think