How I built a transactional hostel allocation engine that eliminates race conditions and double-bookings using MongoDB sessions.

Handling logistics for a 500+ person event—like a major hackathon or campus festival—is easy on paper.

It becomes significantly harder at 2:00 AM when multiple exhausted teams arrive at the registration desk simultaneously while operators manually juggle room assignments.

In this article, I’m pulling back the curtain on the "brain" of Project Morpheus : a transactional allocation engine designed to handle complex accommodation logic without risking data corruption or double-bookings.

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