David Reuel
Villamayor

Tech Lead · Senior Software Engineer

I build and ship software millions depend on. 15+ years writing production code and owning technical delivery across banking and digital identity in Asia, from hard architecture calls to hands-on implementation. Now in Australia, building with AI to sharpen how I ship.

Open to Senior / Staff / Lead Developer roles

Sydney, Australia · Australian PR

LinkedIn GitHub Resume
15+ years in
engineering
8M+ banking
users served
5 ASEAN
countries
200k+ businesses
served
Shipped for

About

I build things that
ship at scale.

David Reuel Villamayor

I design and build production systems at scale, and I stay hands-on with the architecture and the hard calls. I owned technical delivery for UOB, one of Southeast Asia's largest banks, across 5 ASEAN countries. Before that I worked on Singpass and Corppass, the apps that let Singapore residents securely access government and private-sector services.

What I optimise for: systems that hold up under real load and real regulation. I write the code, review the architecture, and stay close enough to the platform to make fast, informed calls. I've led squads when the work called for it, but the depth comes first.

At HCLTech I stayed hands-on as a technical lead, owning delivery for client engagements end-to-end while still writing code and making the architecture calls. Since then I've been building with AI to learn first-hand what it does for a team and a business. I moved to Sydney in January 2026 and found that a decade of compliance-heavy, technical delivery in Singapore maps closely to how engineering teams operate here. Looking for a role where I can build, own hard technical problems, and keep growing.

How I Work

The way I
build things.

01
Technical, not theoretical

I stay close to the code and the hard architecture calls. That depth is how I make better decisions, faster, grounded in the platform's reality rather than a whiteboard.

02
Ownership past the ticket

I don't stop at "done". I think about what breaks in production, what the next engineer inherits, and whether the decision still holds up under real load.

03
Clarity over process

Work moves faster when everyone knows what matters and why. I cut ceremony, make priorities legible, and protect focus so the team can do its best work.

04
Direct, kind feedback

I'd rather flag a problem early than let it calcify. Candour in code review and design discussion is what lets a team trust the work, not just the person.

Experience

Where I've
done the work.

May 2023 – Aug 2025
Technical Lead
HCLTech Singapore

Owned technical delivery for UOB's digital banking platform across 5 ASEAN markets serving 8M customers, hardening defences against a USD 1.7B pan-ASEAN scam landscape.

  • Architected account-drainage detection, working across Product, Business, Fraud, QA, and Operations to identify and block high-risk transactions before funds are drained. Article Watch
  • Delivered facial biometric authentication to secure high-value mobile transactions. Article
  • Supported the Citibank-to-UOB migration, adapting onboarding APIs and verifying data for 2.4M customers migrating onto UOB's platform. Article
  • Certificate of Recognition for Performance Excellence (Mar 2024), ranking in the top 1% of Singapore projects for delivery impact.
Java Spring Boot React.js TypeScript JavaScript IBM MQ Apache Camel Microservices AWS REST APIs Oracle DB PostgreSQL MongoDB Docker CI/CD Grafana Splunk Jenkins SonarQube
Nov 2016 – Dec 2022
Software Engineering Specialist
Accenture Singapore

Built and shipped on Singapore's national digital identity platforms, Singpass and Corppass, serving 5M+ residents and 200k+ businesses.

  • Built the Singpass QR login for 5M+ users at millions of daily auth requests, reaching 95% user adoption while meeting WCAG-AA accessibility standards.Article
  • Migrated Corppass from on-premise to AWS, re-architecting the monolith into microservices with Docker and Kubernetes to streamline access for 200k+ businesses.Article
  • Re-engineered legacy batch processing into real-time APIs, cutting transaction turnaround from 24 hours to sub-second.
  • Mentored junior engineers as the Singapore squad scaled.
Java Spring Boot JavaScript Bootstrap JSP AWS Kubernetes Docker Microservices REST APIs Kafka MySQL Kibana CloudWatch SonarQube CI/CD
Mar 2015 – Oct 2016
Software Developer Senior Analyst
Accenture Philippines

Built client-facing applications across multiple financial services delivery tracks.

  • Delivered AIA Vitality integrations, linking activity tracking and rewards fulfilment into the core insurance platform.
Java Spring REST APIs MySQL JUnit
Apr 2011 – Feb 2015
Software Design Engineer
NEC Telecom Software Philippines

Developed Java applications for NEC's MS5000 R10.0 radio telecom platform.

  • Earned the Presidential Award for product quality and on-time delivery under tight timelines.
Java Spring Framework Swing JPA WebSphere JUnit

Projects

Things I've
built and shipped.

Live
Bank Statement
AI Agent

Upload a bank statement, get back a categorised breakdown. Multi-step agentic reasoning streams in real time so you can watch the model reason as it works. Multi-model support. Just upload a PDF.

Decision: streamed the reasoning loop instead of hiding it. Trust in a finance tool comes from showing the work, not a black-box answer.

Agentic AI ReAct Loop Python Next.js
Live
PDF
Redactor

Drag to highlight any text and black it out with one click. Names, addresses, account numbers. The text is permanently removed from the file, not just hidden. Everything runs in your browser. Your PDF never leaves your device.

Decision: kept all processing client-side. A redaction tool that uploads your sensitive doc defeats its own purpose.

Python FastAPI PyMuPDF PDF.js
In Progress
Cross-Functional Software
Delivery Crew

A question turned into a build: how much of the first sprint can AI absorb? This crew takes a raw PRD and does the delivery prep work autonomously. One agent stress-tests the feature for edge cases and business value. A second proposes data models, API contracts, and infrastructure. A third reviews the architecture against OWASP top 10. Output is Jira-ready tickets. The goal is to cut the overhead that eats team velocity before a line of code is written.

Decision: modelled the agents on a real squad's roles. The value isn't the code, it's the question: where does AI reduce engineering overhead without reducing ownership?

CrewAI Multi-agent AI Agentic AI Python OWASP

Skills

Skills &
Technologies.

Domain
Digital Banking FinTech Gov Digital Services Fraud Prevention
Leadership
Technical Leadership Mentoring & Growth Delivery at Scale Stakeholder Mgmt
Technical & AI
Agentic AI Java Spring TypeScript React Next.js Python AWS Docker Kubernetes Kafka

Certifications

Verified.
Not just claimed.

AWS Certified AI Practitioner badge
AWS Certified AI Practitioner
Amazon Web Services
Jul 2026
Generative AI Leader badge
Generative AI Leader Certification
Google Cloud
Oct 2025
SAFe 6 Agilist badge
Certified SAFe® 6 Agilist
Scaled Agile, Inc.
Oct 2025
PSM I badge
Professional Scrum Master™ I (PSM I)
Scrum.org
Sep 2025

Contact

Let's talk.

Happy to talk about new opportunities in senior or staff engineering, hands-on technical work, or building AI tools. Sydney (AEST/AEDT). I reply to every email within 24 hours.

davidreuelvillamayor@gmail.com