Product engineering
Web and mobile products end to end: React & Next.js frontends, React Native apps, NestJS services, and the AWS, Docker, and GitHub Actions plumbing that ships them.
- React
- React Native
- NestJS
- AWS
Full Stack Engineer · Jakarta, Indonesia
I build production web & mobile products — and the AI‑native features inside them.
Hi, I'm Muhammad Farrel Fauzan. Four years of shipping TypeScript across React, React Native, and NestJS for fintech, edtech, insurance, and streaming teams — from LLM gateways and real-time streaming to billing and video infrastructure on AWS.
$ whoami
farrel — full stack engineer, jakarta
$ cat stack.txt
typescript · react · react-native · nestjs · aws
$ ls ./shipping
llm-gateways/ streaming-ai/ billing/ video-infra/
$ cat AGENTS.md | head -1
# contracts so agent output lands review-ready
$ - Years in production
- 4+
- Teams shipped with
- 7
- Industries
- 4
- Countries
- 3
fintech · edtech · insurance · streaming
Indonesia · France · Singapore
01 — About
Three things I do well.
Deep TypeScript across the stack, backed by hands-on AWS deployment and CI/CD — plus a working method for getting real, reviewable code out of AI coding agents.
AI-native features
Provider-agnostic LLM gateways, token-by-token streaming, speech-to-text, structured output that maps onto UI, and prompt-injection hardening with audit trails.
- LLM gateways
- Streaming
- Whisper
- Guardrails
Agentic delivery
Claude Code, Cursor, Codex, and MCP workflows built around written implementation contracts (AGENTS.md / CLAUDE.md), so AI-generated code arrives review-ready.
- Claude Code
- Cursor
- MCP
- AGENTS.md
02 — Experience
Where I've shipped.
Seven teams across streaming, AI tooling, digital securities, climate, HR, government, and insurance.
-
Full Stack Engineer · StoryBox
Short-drama vertical video streaming
- Built the dashboard and business-intelligence layer tracking content performance, subscription health, and revenue — a single source of truth for content decisions.
- Integrated Google Play Billing and Xendit for subscriptions, recurring payments, and transaction reconciliation across web and mobile.
- Shipped admin tooling for subscription state, VIP access control, and payment history, cutting manual support handling for billing issues.
- Architected client state with Zustand and TanStack Query, standardising caching, invalidation, and optimistic updates.
- Owned media infrastructure on AWS: S3 bucket policies, prefix-scoped access, and CloudFront distributions with HLS-compatible CORS for video delivery.
- Debugged and optimised the Flutter/Dart mobile client, improving startup stability and playback performance.
- AI-assisted delivery: drove feature work through Claude Code and Cursor with a maintained CLAUDE.md context spec and MCP servers, using agentic multi-file refactors for migrations and test scaffolding.
- Zustand
- TanStack Query
- Google Play Billing
- Xendit
- S3 · CloudFront
- Flutter
- Claude Code
-
Full Stack Engineer · Intiva
AI meeting assistant
- Built AI meeting summarisation into a React Native app — the full path from live capture to structured, user-facing summaries.
- Implemented WebSocket transport for token-by-token streaming of AI output and WebRTC for live audio/video capture, keeping perceived latency low during long meetings.
- Designed and shipped folder management for AI-generated summaries so users can organise, search, and retain meeting knowledge.
- Tuned prompt structure and output schemas so summaries returned consistent, parseable sections that mapped directly onto UI components.
- React Native
- WebSocket
- WebRTC
- LLM streaming
- Structured output
-
Backend Engineer · Equisafe
Digital securities platform
- Developed and maintained NestJS backend services with a clean-architecture approach and optimised query integration.
- Implemented message queuing and background job processing with BullMQ for long-running and retry-sensitive workloads.
- Authored a typed Client SDK that removed integration guesswork for the frontend team and reduced API onboarding time.
- NestJS
- BullMQ
- Clean architecture
- Typed SDK
-
Senior Full Stack Engineer · K-Labs
- Led development of Daunplus, a platform helping Indonesian businesses track and manage corporate emissions — owning architecture and delivery end to end.
- Built React frontends around reusable components and a clean UI architecture, with Redux Toolkit for predictable state across complex reporting flows.
- Developed NestJS backend services covering business logic, calculations, and API integration.
- Collaborated cross-functionally to maintain LMS features for Bina Bangsa School.
- React
- Redux Toolkit
- NestJS
- Tech lead
-
Full Stack Engineer · Sari Baut Net
- Built a NestJS proxy API integrating chatbot services with internal systems and external platforms, with secure, reliable message handling in both directions.
- Delivered a Human Resource Management application for AntaraCo with Ionic + Nuxt 3 and a NestJS backend.
- NestJS
- Nuxt 3
- Ionic
- Chatbot integration
-
Application Developer · Otorita Ibu Kota Nusantara
Nusantara Capital Authority
- Helped define the smart-city technology concept for IKN with Deloitte, covering architecture, data integration, and digital infrastructure.
- Built a project monitoring dashboard enabling stakeholders to track progress and operational metrics for large-scale urban projects.
- Designed reporting features supporting decision-making at national programme scale.
- Dashboards
- Reporting
- Smart city
- GovTech
-
Full Stack JavaScript Developer · Embreo Pte Ltd
Insurance
- Developed insurance web applications with React.js, using Redux Saga to manage complex asynchronous workflows and business logic.
- Built insurance services for quotation, remarketing, and user management with Express.js.
- React
- Redux Saga
- Express.js
03 — Featured project
Saling Jaga Health Management System
A production-grade HMS for Indonesian clinics and hospitals — patient, doctor, appointment, registration, and pharmacy flows in a modular monolith designed to split into services.
Ongoing
View repository
Frontend
Next.js App Router
CASL rules mirrored for route & component visibility
Zod schemas
shared contract
API · modular monolith
NestJS
Domain → application → infrastructure → presentation, per module
- patient
- doctor
- appointment
- registration
- pharmacy
Deny-by-default RBAC · CASL guards with ownership checks
adapter
timeout · retry · breaker
AI gateway
Multi-provider LLM
- OpenAI
- Anthropic
- DeepSeek
- Ollama
Every prompt & response persisted for audit · no diagnostic or prescriptive output
Data
PostgreSQL · Prisma
Indonesian health ecosystem
- SATUSEHAT
- BPJS Antrean
- RME retention
- Telegram
AWS CDKDocker ComposeGitHub Actionspnpm monorepo
Clean architecture, per module
A pnpm monorepo with a NestJS API and Next.js frontend. Each module keeps domain, application, infrastructure, and presentation layers so the monolith can split into services later.
Deny-by-default RBAC
Action-based CASL permissions with resource-ownership checks enforced in Nest guards — mirrored in the UI for visibility, with the backend as the source of truth.
Multi-provider AI gateway
Clinic admins choose OpenAI, Anthropic, DeepSeek, or self-hosted Ollama. Requests flow through an adapter with timeout, retry, and circuit-breaker policy, and every exchange is audited.
Security by design
A prompt-injection threat model and manual test suite for the clinical chatbot, alongside MFA, TLS, secrets, and file-upload policies — with hard boundaries on diagnostic output.
Local health integrations
SATUSEHAT, BPJS Antrean onboarding, RME retention, and WhatsApp/Telegram patient notifications, each with documented go/no-go criteria.
CI on every PR & AGENTS.md
Lint, typecheck, unit and DB-backed integration tests, Prisma migration checks, and image builds — plus a repo-wide AGENTS.md contract with per-workspace scope and reusable skills.
04 — Skills
The toolbox.
Languages
- TypeScript
- JavaScript
- Python
- Dart
- SQL
Frontend
- React
- Next.js (App Router)
- React Native
- Expo
- Flutter
- Nuxt 3
- Ionic
- Tailwind CSS
State & data
- Zustand
- TanStack Query
- Redux Toolkit
- Redux Saga
Backend
- NestJS
- Express.js
- REST / OpenAPI
- WebSocket
- WebRTC
- BullMQ
- PostgreSQL
- Prisma
- Zod
- CASL (RBAC)
- JWT
AI engineering
- Multi-provider LLM gateways
- Anthropic · OpenAI · DeepSeek · Ollama
- Prompt design & structured output
- Streaming responses
- Speech-to-text (Whisper)
- Prompt-injection defence
- AI audit logging
AI-assisted development
- Claude Code
- Cursor
- Codex
- AGENTS.md / CLAUDE.md contracts
- Per-workspace agent scoping
- Reusable agent skills
- MCP servers
- Agentic multi-file refactoring
Cloud & infra
- AWS S3
- CloudFront
- EC2
- IAM
- CDK
- Docker & Compose
- GitHub Actions
- pnpm monorepos
- Nginx
- Caddy
Domain & integrations
- SATUSEHAT
- BPJS Antrean
- RME retention
- WhatsApp / Telegram Business APIs
- Xendit
- Google Play Billing
- Subscription & recurring billing
05 — Contact
Have a product to ship? Let's talk.
Open to full-stack and AI engineering roles, remote or in Jakarta.