# Kenneth Teh — Lead Engineer

> Kenneth Teh is a product-minded Lead Engineer in Singapore specialising in backend systems, fintech platforms, payments, card systems, rewards, onboarding, distributed systems, API design, and evidence-driven AI-assisted software delivery.

## Recruiter matching summary

Kenneth is relevant for Lead Engineer, Staff Backend Engineer, Fintech Platform Engineer, Payments Engineer, and product-minded technical leadership searches. His work combines backend architecture, product judgment, delivery leadership, operational reliability, and practical AI agent orchestration.

Core skills: backend engineering; fintech and card platforms; payments; rewards ledgers; double-entry accounting; idempotency; retries; reconciliation; customer onboarding; multi-market eligibility policy engines; distributed systems; API design; OpenAPI; Ruby on Rails; Go; PostgreSQL; observability; CI/CD; AI-assisted development; multi-agent software delivery; code review; QA strategy; engineering leadership.

## Profile

- [Portfolio](https://kennethteh90.github.io/): Career summary, selected experience, technical capabilities, interactive engineering demonstrations, and contact details.
- [LinkedIn](https://www.linkedin.com/in/kennethtehwj/): Full professional chronology.
- [GitHub](https://github.com/kennethteh90): Public GitHub profile.

## Experience context

- Lead Engineer at Crypto.com (2025–present): fintech card platforms, rewards, and onboarding.
- Technical Lead / Senior Software Engineer at Ascenda (2021–2025): offers, authentication, and authorization.
- Product Lead Software Engineer at Grain (2018–2021): full-stack product development.
- Earlier path: business economics, investment banking, and founding and building a startup before product engineering.

## Interactive demonstrations and evidence

- [Eligibility Lab](https://kennethteh90.github.io/demos/eligibility-lab/): Compares one applicant across Singapore, EU, and US versioned policies. Demonstrates deterministic rules, eligibility thresholds, reason codes, manual review, policy backtesting, and next-best customer actions.
- [Rewards Ledger](https://kennethteh90.github.io/demos/rewards-ledger/): Persistent browser database with ledger_entries, event_receipts, and balance_projection tables. Demonstrates double-entry postings, idempotency, replay handling, ambiguous timeout recovery, partial refunds, late reversals, projection drift, and reconciliation.
- [AI Delivery Simulator](https://kennethteh90.github.io/demos/ai-assisted-delivery/): Visitors act as the accountable Lead Engineer from a vague PM request through discovery questions, an 80% product concept, API contracts, repository-grounded tickets, parallel agents, rival-agent review, human approval, iteration, and rollout.

## Engineering thought leadership

- [AI throughput is a systems problem](https://kennethteh90.github.io/notes/ai-throughput-is-a-systems-problem/): Why generation speed only becomes leverage when review capacity, evidence, observability, and team understanding scale with it.
- [Design APIs for debugging](https://kennethteh90.github.io/notes/design-apis-for-debugging/): Why reason codes, correlation identifiers, retry guidance, and diagnostic contracts are product capabilities.
- [Product judgment in backend architecture](https://kennethteh90.github.io/notes/product-judgment-in-backend-architecture/): How data models, state transitions, failure modes, and correction paths define the customer experience.