← All projects
01engineering
CBT Pustaka Mulia
CBT Pustaka Mulia is a production-grade Computer-Based Test platform built for PT Pustaka Mulia Sejahtera to serve national TKA (Tes Kemampuan Akademik) exam simulations at scale. The system is engineered to handle 5,000+ concurrent users per session and 10,000–15,000 users per day, with zero tolerance for answer loss or race conditions.
Key contributions
- Architected the full system on a Turborepo monorepo with Next.js frontend + Express.js backend
- Implemented async BullMQ scoring pipeline decoupling submission from scoring for horizontal scalability
- Built atomic Redis DECR token quotas preventing race conditions under concurrent load
- Designed heartbeat auto-save (30–60s intervals) guaranteeing zero answer loss on network failure or refresh
- Designed a 6-tier RBAC system: Admin, Operator Sekolah, Guru, Siswa, Kepala Sekolah, Orang Tua
- Built Admin CMS with real-time monitoring dashboard, token lifecycle management, and question bank management
roleFull-Stack Engineer
year2025
typeengineering
Stack
Next.jsExpress.jsPostgreSQLRedisBullMQTurborepo