Projects

Each project below is written as problem, architecture, key decisions, failure handling, observability, result, and lessons learned — not a technology list.

RelayHub

Live

Event-driven Integration Platform

An event-integration platform: events are ingested, validated, transformed, and delivered to downstream targets with retry, dead-letter handling, replay, and metrics — this site's Live Monitoring page reads its real, live delivery and DLQ data directly.

Java
Spring Boot
Kafka
PostgreSQL

English Core Speaking

Live

User-facing Learning SaaS

A full-stack English speaking practice service: a NestJS backend and Vue 3 frontend, with OAuth-based sign-in and an external AI/LLM API integration for evaluating spoken responses.

NestJS
Vue 3
PostgreSQL
Prisma

See these projects running for real

RelayHub's own delivery, DLQ, and ingress data — pushed live from the deployed service, not a screenshot.

Open RelayHub Live Case Studies