Williams Yeo

Critical internal platform for a major short-term rental player.

• Tech lead: target architecture and clear service/domain boundaries

• Managed the migration from microservices to a modular monolith (maintainability, performance, velocity)

• NestJS back-end and Next.js front-end, clear structuring of business domains

• Interventions on the React Native mobile app; stack stabilization and documentation

• Mentoring of an intermediate developer

Stack: NestJS, Next.js, TypeScript, React Native, Kubernetes, PostgreSQL, Playwright/Jest, GitHub Actions

SaaS for management/CRM for beauty/wellness freelancers, designed and operated solo. ~100,000 users.

• Scalable serverless back-end on GCP (Cloud Run, Functions, Pub/Sub) + Firestore, strict security rules

• End-to-end product: invitation by signed link (JWT), role management, Stripe Checkout & webhooks (3D Secure)

• OTP authentication, server-side sessions, strictly server-side sensitive logic

• Cross-platform React Native application; team recruitment and management

Deployment of a multi-agent AI platform: 5 specialized agents (memory, escalation, prompt versioning), orchestration via Vercel AI SDK with multi-provider fallback (Anthropic/OpenAI via AI Gateway), MCP servers anchoring LLMs to business data (RAG), all designed with GDPR by design.

Stack: Next.js, Node.js, NestJS, GCP, Firestore, Redis, Stripe, React Native · Vercel AI SDK, MCP, RAG · Sentry, Jest/Playwright/Detox, GitHub Actions

Development of the TrendSpotter platform for detecting future beauty trends worldwide.

• Code audit, best practices improvement, and new features

• Serverless architecture and data exploitation on GCP (Cloud Run, Cloud Functions, BigQuery)

• Agile project management (one-week sprints) with a team of 3 developers

Stack: ReactJS, Node.js, Styled Components, Ant Design, Firebase, GCP (Cloud Run, Cloud Functions, BigQuery), TypeScript · Jest · GCP Cloud Monitoring & Logging