AI / Fintech Systems
AI Trading Copilot
Self-hosted market research and trading workstation with broker tools, multi-agent analysis, and gated execution paths.
Nuxt FastAPI LangGraph PostgreSQL
Hello, world. I'm
JJ Teoh
Mechatronics engineer turned software developer. I build reliable AI systems, SDKs, and self-hosted infrastructure.
About
I came to software from mechatronics. Control systems, embedded hardware, things that fail in the field. So I build software the way I'd build a machine: for failure modes and data flow, not just the happy path.
Distributed systems
Offline-first sync, edge computing, and data that survives bad networks.
Full-stack product
End to end. Schema and API design through to a polished, shipped interface.
Infrastructure
Containers, pipelines, and the operational glue that keeps things alive in prod.
Selected work
A few systems I've built end to end. Self-hosted, strongly typed, and full of the edge cases that show how I think.
SDK / Full-Stack
Repro Feedback SDK & Dashboard
Framework-agnostic feedback widget with annotated screenshots, session replay, diagnostics, and a self-hostable Nuxt dashboard.
Nuxt Preact TypeScript PostgreSQL
More work
Experience
Back End Developer
Studio20 · Full-time
Kuala Lumpur · Hybrid
- Built MyInvois e-invoicing compliance end to end: document validation, PKI signing, and LHDN integration.
- Shipped NestJS APIs with role-based access and multi-tenant isolation, plus the team's CI/CD.
Software Developer
ViTrox Corporation Berhad · Part-time
Remote
- Ship features for an internal web app used across business units.
- Built a cross-platform desktop tool (Tauri, Vue, SQLite) with offline-first background sync.
Industrial Trainee
ViTrox Corporation Berhad · Internship
Penang · On-site
- Built a full-stack app for real-time data viz and IoT device control (Nuxt 3, Quasar).
- Integrated embedded communication protocols directly with the hardware teams.
Data Entry
i-SURVY SDN BHD · Part-time
Remote
- Automated report generation with Python, cutting manual processing time.
Toolkit
Languages
TypeScript JavaScript Rust Python SQL
Frontend
Vue Nuxt React Preact Next.js Expo Tailwind CSS Three.js Shadow DOM
Backend
Node.js NestJS FastAPI Elysia.js Hono Mastra AI SDK LangGraph REST GraphQL WebSocket
Databases
PostgreSQL SQLite Drizzle Redis MongoDB
Infrastructure & DevOps
Docker CI/CD Linux Nginx GitHub Actions Bun
Tools & Practices
Git TDD Vitest Jest Playwright Monorepos SDK Design GitHub Apps Tauri ElectricSQL PKI/X.509
System design
A cleaner slice through the data flows and integration boundaries behind the work.
AI Trading Copilot
Tool-calling chat, streaming research runs, LangGraph decision pipeline, and gated broker execution.
Repro Feedback Platform
Framework-agnostic widget capture flowing into a self-hosted intake API and triage dashboard.
Edge Sync Engine
Offline-first local state, ElectricSQL shape sync, Hono API routes, and Postgres-backed convergence.
Contribution activity
Get in touch!
Have a project in mind, want to collaborate, or just say hello? Drop me a message.