Bitotsav '26 — High-Concurrency Cloud Architecture for 5,000+ Live Users
End-to-end engineering leadership of the complete festival platform: offline-resilient QR access verification, low-latency Redis caching, and real-time operational telemetry.
5,000+
Live Participants
99.99%
Festival Uptime
< 40ms
Check-in Scan Latency
0
Gate Failures / Breaches
1. The Challenge: Heavy Concurrency Under Edge Network Variance
Bitotsav is one of Eastern India's largest collegiate cultural festivals, bringing together thousands of participants across sports, fine arts, drama, dance, and flagship music nights.
The primary architectural challenge was ensuring zero gate bottlenecks: university gates and auditorium entry points experience extreme mobile network throttling when thousands of students gather simultaneously.
2. Cryptographic Offline-Tolerant QR Verification
Traditional online QR scanners fail when cellular towers get congested. We engineered a dual-validation cryptographic protocol:
Participant QR codes encode cryptographic payload signatures with embedded expiration nonces, preventing screenshot duplication and anti-forgery passes.
Volunteer scanner PWA devices pre-sync indexed bloom filters of valid registrations, verifying authenticity in sub-40ms even during complete internet blackout.
3. Low-Latency Redis State Caching
To shield the primary PostgreSQL database from sudden bursts during celebrity concert ticket drops and leaderboard updates, all hot paths were proxied through a Redis cluster:
- Write-Behind Check-In Logging: Scans were acknowledged immediately in Redis and flushed asynchronously to PostgreSQL in batch queues.
- Distributed Rate Limiting: Enforced sliding-window rate limiters preventing automated bot booking scripts.
4. Engineering Leadership Takeaway
High-stakes event systems require defensive design at every layer: From presenting security architecture to university leadership to running 72 hours of uninterrupted live production operations, Bitotsav demonstrated how resilient distributed primitives deliver flawless real-world experiences.