JLPT National Registration System

Engineered the high-traffic backend behind the JLPT (Japanese-Language Proficiency Test) national registration platform — supporting online applications, payments, and scheduling at exam-day load.

National JLPT exam registration in Myanmar faced massive traffic spikes on opening day, historically causing system timeouts, database lock contention, and dropped payment transactions during high-stakes candidate registration.

Engineered high-throughput Java/Spring Boot backend with PostgreSQL connection pooling, pessimistic slot reservations, automated Cypress end-to-end validation, and 2C2P payment reconciliation with idempotency keys.

Shipped a system that sustained 5,000+ peak concurrent payment users with zero downtime, and integrated the 2C2P payment gateway end-to-end. Earned the President's Award for Best System Development.

• ◆Designed registration backend for peak-day concurrent load.
• ◆Integrated 2C2P payment flow with reconciliation & retries.
• ◆Built Cypress end-to-end coverage of the candidate journey.
• ◆Tuned PostgreSQL queries for slot-allocation hot paths.