JJ Teoh
Software Developer
AI Systems, Product Infrastructure & Full-Stack Platforms
Mechatronics engineer turned software developer. I build complex, reliable products — from AI trading copilots and embeddable feedback SDKs to edge sync engines, financial platforms, and compliance infrastructure.
About
I started in mechatronics engineering — designing control systems and working with embedded hardware. That foundation in systems thinking shapes how I approach software: I think in terms of failure modes, data flow, and operational constraints, not just features and frameworks.
Distributed Systems
Building reliable data synchronization, offline-first architectures, and edge computing solutions that work in constrained environments.
Full-Stack Product Engineering
End-to-end application development from database design and API architecture to polished user interfaces and deployment pipelines.
Infrastructure & DevOps
Container orchestration, CI/CD pipelines, monitoring, and the operational tooling that keeps systems running in production.
Featured Projects
Complex, self-hosted builds with real integrations, typed backends, durable storage, and enough edge cases to show how I think through systems.
2
flagship builds
AI
agents + tools
OSS
SDK mindset
AI Trading Copilot
Self-hosted market research and trading workstation with broker tools, multi-agent analysis, and gated execution paths.
Nuxt + FastAPI
10-role pipeline
market + account tools
Dockerized stack
- Streams candlestick charts, tool calls, analyst reports, debate turns, risk reviews, and final decisions as structured NDJSON.
- Wraps moomoo OpenD for watchlists, k-lines, paper portfolio reads, and gated order execution from a Python FastAPI service.
- Persists chat, algo state, LangGraph checkpoints, and per-role reflections in a shared Postgres schema.
Problem
Retail trading workflows were scattered across broker terminals, watchlists, news tabs, portfolio trackers, and LLM chats with no shared context or audit trail.
Approach
Built a Dockerized Nuxt + FastAPI system where an AI chat can call broker tools, stream real market charts, mutate moomoo watchlists, read positions, and run a LangGraph TradingAgents research pipeline with analyst, debate, risk, and portfolio-manager roles persisted to Postgres.
Impact
Turns live market data, watchlists, portfolio state, news, and multi-agent research into one streaming interface with paper/live trading gates.
Repro — Feedback SDK & Triage Dashboard
Framework-agnostic feedback widget with annotated screenshots, session replay, diagnostics, and a self-hostable Nuxt dashboard.
SDK + dashboard
30s replay
script + ESM
self-hostable
- Ships a host-isolated widget that works across vanilla JS, React, Vue, Svelte, Angular, Nuxt, and Next.js apps.
- Collects annotated screenshots, DOM replay, console logs, network logs, cookies, and browser/system info automatically.
- Includes a Nuxt triage dashboard, Chrome tester extension, project keys, origin allowlists, blob storage adapters, and GitHub issue sync.
More Systems Work
Edge Device Sync Engine
Offline-first bidirectional sync between IoT field devices and cloud infrastructure.
Hospitality Management Platform
Unified PMS, POS, and e-invoicing system for hotel operations.
Fitness Coaching Platform
Cross-platform coaching tool with web dashboard, mobile app, and native health integrations.
E-Invoicing Compliance SDK
Published npm SDK for Malaysian e-invoicing with digital signing and rate limiting.
AI Trip Planner
AI-powered travel itinerary planner with real-time collaboration, expense tracking, and Google Maps integration.
Experience
Back End Developer
Studio20 · Full-time
Bangsar, Kuala Lumpur · Hybrid
- Built e-invoicing compliance system (MyInvois) with document validation, PKI digital signing, and API integration with LHDN
- Developed backend services and REST APIs using NestJS with PostgreSQL and MongoDB
- Implemented role-based access control and multi-tenant data isolation for internal platform
- Set up CI/CD pipelines and established code review workflows for the backend team
Software Developer
ViTrox Corporation Berhad · Part-time
Remote
- Maintain and ship features for internal web application used across business units
- Built cross-platform desktop application for user management using Tauri, Vue, and SQLite
- Implemented offline-first data handling with background sync for desktop tooling
Industrial Trainee
ViTrox Corporation Berhad · Internship
Penang, Malaysia · On-site
- Built full-stack web application for real-time data visualization and IoT device control
- Implemented frontend with Nuxt 3, Quasar, and Tailwind CSS connected to device APIs
- Worked directly with hardware teams to integrate embedded communication protocols
Data Entry
i-SURVY SDN BHD · Part-time
Malaysia · Remote
- Automated report generation workflows using Python scripts and Excel templates
- Reduced manual data processing time through scripted pipelines
Skills & Technologies
Languages
Frontend
Backend
Databases
Infrastructure & DevOps
Tools & Practices
System Design
Cleaner slices through the main data flows, integration boundaries, and persistence layers behind the project 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.
Get in touch!
Have a project in mind, want to collaborate, or just say hello? Drop me a message.