Open to AI-native engineering roles

Kelvin You

AI-native Software Engineer

I build agents I don't trust — so they audit each other. Day job: payment software on a platform serving 9,000+ users.

How I Work

Payments taught me what it costs when a system is quietly wrong. I build agents like those stakes carried over.

9,000+
Users in production
4 agents
Debate pipeline, self-scored
RN + Kotlin
Front and back, shipped
Portrait of Kelvin You Kok Eng

Kuala Lumpur, Malaysia

Currently Building

A multi-agent stock-analysis pipeline on the Claude Agent SDK — four analyst agents, a debate stage, and an outcome-memory loop that scores its own past calls.

See the pipeline

Skills

Three layers, one glance. The marker says how far each has gone — filled means it ran in production for paying users.

●Shipped to paying users○Built in my own systems

AI systems

Personal-OS · ai-stock-analysis — public repos, weekly cadence, no paying users

  • LLM Integration (Claude API) — Built in my own systems
  • Claude Agent SDK — Built in my own systems
  • MCP (Model Context Protocol) — Built in my own systems
  • Multi-agent Systems — Built in my own systems
  • RAG — Built in my own systems
  • Claude Code — Built in my own systems

Interface

dtcpay app · Simpletruss · Tencent / MiHoYo analytics dashboards

  • TypeScript — Shipped to paying users
  • React — Shipped to paying users
  • React Native — Shipped to paying users
  • Next.js — Shipped to paying users
  • GraphQL — Shipped to paying users
  • Apollo Client — Shipped to paying users

CourseworkFlutter

Server & data

dtcpay payments backend, Kotlin · PTIB, paid for by 3 centres

  • Kotlin — Shipped to paying users
  • Spring Boot — Shipped to paying users
  • PostgreSQL — Shipped to paying users
  • Supabase — Shipped to paying users
  • Python — Built in my own systems
  • Node.js — Built in my own systems
  • FastAPI — Built in my own systems

CourseworkJava · Solidity · Dask · scikit-learn · pandas

Ship & ops

  • Vercel — Shipped to paying users
  • Git — Shipped to paying users
  • Docker — Built in my own systems
  • GitHub Actions (CI/CD) — Built in my own systems
  • Playwright — Built in my own systems

CourseworkFirebase

Studied, never shipped

Go · Redis · AWS · Kubernetes— current learning target, kept off the resume

Projects

Each one with the measured result it produced — and an honest blank where there isn't one.

Agentic systems2026

Multi-Agent Stock Analysis

Four analyst desks — fundamentals, technical, sentiment, macro — each on its own MCP server, argued through a debate stage and merged by a synthesizer. Signals are validated walk-forward against a frozen holdout, with Wilson intervals and a deflated Sharpe on the strategy search — which is how I know the factor still lagged buy-and-hold.

Python · Claude Agent SDK · MCP · RAG · Multi-agent Systems · Walk-forward Backtesting · Pydantic · FastAPI

1.32
Sharpe on a frozen 2023-26 holdout, net of cost
10/12
tickers still net-positive at 30 bps/side
Source

2026

Personal-OS

Guardrail design over raw model output. Only an acute bad-sleep night is non-overridable; on the noisier 7-day trend, live HRV overrides the automated deload — so it catches real risk without crying wolf every week on a lagging metric.

Claude Code · MCP · LLM Integration · Multi-agent Systems · Python · TypeScript · Agent Skills

12
agent skills running on a weekly cadence
1
non-overridable rule; the rest defer to live HRV
Source

2025

PTIB

Multi-tenant SaaS that digitised a 200-student tuition centre: role-based portals, Stripe billing, QR attendance, row-level security in Supabase.

Next.js · TailwindCSS · Supabase · PostgreSQL · Stripe · Shadcn · React

$500
MRR from 3 pilot centres
5 hrs
of admin saved per week
Demo
All 8 projects

Experience

From production fintech platforms to agentic systems I build on my own time.

2025

NOW

1 yr 4 mos

Full-timeKuala Lumpur, Malaysia

Frontend Engineer

DTCPay (FinTech)

Production payments platform, 9,000+ users. Led Flutter to React Native migration unifying mobile + web.

  • Kotlin + Spring Boot cross-currency batch payments: locked FX quotes, cent-exact splits, duplicate guard.
  • PII masking across 5 payment surfaces, fail-closed: data stays masked unless explicitly classified corporate.
  • AML review (KYT) UI: maker-checker approvals, request-for-info state machine, scoped decisions.
  • Cross-system live E2E (Playwright): Wallet → TOP → bank callback → ledger checks, agent-operable runbooks.

Kotlin · Spring Boot · React · React Native · TypeScript · Payment Systems · Concurrency · System Design

Wrote about this16

The Status Column Is the Lock: Duplicate-Submit Protection Without an Idempotency KeyMaking the Rows Add Up: Rounding in a Cross-Currency Batch PaymentFail-Closed: Picking the Conspicuous Failure Over the Silent OneFour Eyes, One Status Column: Modelling a Maker-Checker Review WorkflowNo Test Runner: Verifying a Migration by Triangulating Three Blind Tools
11 more
545 Migrations in a Shared JARChecking Idempotency Against the Wrong ClockThe Update That Reverted Someone Else's UpdateThree Copies of the Same Rule, Three Different Answers for ZeroThe Guard Kept Running, It Just Stopped Being Able to FailThe Flag Meant 'Done', But 'Done' Hadn't Happened YetDisabling It Did Nothing, Because 'Off' and 'Never Set' Looked the SameThe Permission Check That Was Right for the Old CallerA Cache Rebuild Looked Exactly Like a New LoginThe Merge Conflict That Compiled Clean and Broke at RuntimeComputed Once, Wrong Forever

2024

2025

1 yr 1 mo

Full-timeKuala Lumpur, Malaysia

Frontend Engineer

Simpletruss

Vendor SaaS (LessenPro) for Lessen, a US property-services operator.

  • Built and owned the shared React component library (TypeScript, Storybook) behind LessenPro's screens.
  • Apollo cache: cache.modify list writes instead of refetchQueries, so new tickets skip a full list refetch.
  • Mobile-first responsive rebuild of the vendor app, with design and backend teams.

React · TypeScript · GraphQL · Apollo Client · Zustand · Material UI · Storybook

LessenPro

Demo

Scheduling engine, vendor coordination, maintenance tracking.

React · TypeScript · GraphQL · Material UI · Apollo Client

Wrote about this1

The Cache Doesn't Know About Your List: Apollo Normalization in Practice

2023

2024

10 mos

Full-timeKuala Lumpur, Malaysia

Frontend Developer

Beyondsoft (Tencent)

Game analytics platform (DataBrain) for Tencent's Level Infinite.

  • Shipped 15+ features in a qiankun micro-frontend (React, Umi, Ant Design) for user-configurable dashboards.
  • 100K-row tables: Web Worker parsing, infinite scroll, memoized chart/table components to cut re-renders.
  • Delivered from Chinese-language specs with Tencent product and engineering teams across time zones.

React · TypeScript · Redux · Ant Design · Jest · Docker · Webpack · Go

Databrain Global

Demo

Real-time player analytics. 100K+ row datasets, complex filters, interactive dashboards.

React · Umi.js · Ant Design · TypeScript · Go

Wrote about this1

Every Boundary Leaked: A Year of Micro-Frontends at Tencent Scale

2023

2023

6 mos

InternshipKuala Lumpur, Malaysia

Java Software Engineer Intern

Finexus (Fintech)

Legacy fintech Java applications: new payment features, test coverage, deployment scripts.

  • Extended legacy Java applications with payment processing features, with unit and integration tests.
  • Shell scripts to automate Tomcat deployments and streamline release configuration.

Java · Oracle SQL · Servlets · JSP · Tomcat · Shell Scripting · SOAP

2020

2021

4 mos

InternshipKuala Lumpur, Malaysia

Software Engineer Intern

Techtics (Web3)

Ethereum dApp with MetaMask signing, plus a jQuery → React rebuild of the legacy frontend.

  • Migrated the legacy jQuery frontend to React.
  • Built a dApp connecting Solidity smart contracts to MetaMask for transaction signing.
  • Real-time exchange-rate feeds, authentication flows and REST APIs for transaction management.

React · TypeScript · Solidity · MetaMask · Laravel · Node.js · Express

Education

Two credentials, one institution, four unbroken years. Certificates and transcripts are on file.

Tunku Abdul Rahman University of Management and Technology

Kuala Lumpur, Malaysia2019 – 20234 yrs 2 mos unbroken

3.72

CGPA

Dean's List

top 10% of cohort

CertificateTranscript

Bachelor (Hons)2021 – 2023

Software Engineering (Honours)

Distributed systems, parallel computing and performance optimization, carried through 15+ builds — blockchain dApps, mobile apps, graphics.

  • Final year project — an offline-first travel guide app, built as a two-person team
  • Earned the Finexus (fintech) internship on university recommendation
Core
Data Structures & Algorithms · Distributed Systems · Parallel Computing · Human-Computer Interaction · Graphics Programming
Electives
Mobile Development (Flutter) · Blockchain Development (Solidity) · Data Science (Python)

3.7439

CGPA

Transcript

Diploma2019 – 2021

Computer Science

Where the fundamentals came from: object-oriented Java, then down to C and assembly, against a full mathematics track.

Core
Object-Oriented Programming (Java) · C & Assembly · Algebra · Calculus · Statistics · Discrete Mathematics
Kuala Lumpur · GMT+8Replies within a dayOpen to conversations

Start a thread

Email's the fastest route to me. Pick a subject and the draft below lands in your mail client, already written.

Toykekelvin0220@gmail.com
Re

Hi Kelvin — we're hiring a full-stack engineer and your payments work looks like a fit. Here's the team and the scope —

Open in mail client
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