Backend
vSTU Learning Platform
Year
2024 – 2026
Role
Backend Engineer
Category
Backend
Stack
Node.js, NestJS, Express.js, MongoDB, PostgreSQL, Prisma, Socket.IO, Docker
About the Project
An ed-tech platform for K–12 students, offering quizzes, contests with live leaderboards, prizes, tutoring and parental controls. As backend engineer I designed and delivered the backend, from the first service to a production platform with 1000+ paying subscribers.
Visit vstu.et ↗Subscriptions & billing
Integrated Ethio Telecom's SOAP subscription API (airtime and Telebirr billing). An idempotent callback handler deduplicates on transaction ID and drives the subscription lifecycle and the gating of paid content, supporting 1000+ paying subscribers.
Live tutoring
Real-time tutoring sessions built with Socket.IO and WebRTC signalling, including authenticated rooms, recurring scheduling via cron, and real-time notifications.
Points, prizes & leaderboards
A points and prize-redemption system with exactly-once point awards and stock and cost checks, plus weekly and yearly leaderboards built on aggregation pipelines.
60+ REST modules
Backend design and delivery across quizzes, prizes, leaderboards, tutoring and parent controls, documented with Swagger.
Live production migration
Migrated the platform from MongoDB and Express to PostgreSQL, Prisma and NestJS with a 44-file relational schema and 41 ordered, dependency-validated data-migration scripts, run alongside live production traffic by mirroring telecom callbacks to the new service.
Analytics & AI
An admin analytics suite covering revenue, subscriptions and engagement from daily to annual periods, and an AI quiz generator using Gemini structured output.
Infrastructure
CI/CD with GitHub Actions, GHCR and SSH deploys, Docker Compose environments, Memcached caching behind feature toggles, and multi-core clustering.
