Payments × Engineering · Atlanta

Hi, I'm Thomas. I build solutions that move money.

For nearly a decade I've worked across payments end to end: mobile SDKs, EMV terminal fleets, gateways and in-store platforms. Today I'm a payments technical lead and Stripe-certified architect designing payment solutions for clients, and I'm exploring how AI coding agents can work safely in codebases where every mistake has a dollar amount.

Card-present · EMV · P2PE · Tokenization · PCI DSS · Distributed systems · Agentic development

Thomas Fuller

Solutions

Payment systems I've designed and built

Full résumé LinkedIn ↗
  1. Store checkout
  2. Card-present services
  3. Processor

Retail

In-store card payments for a national retailer

Card-present transaction handling behind every in-store sale, built cloud-native on Google Cloud.

  • Services on Cloud Run and GKE, backed by Cloud SQL and Pub/Sub.
  • Internal tooling and coding standards that sped up the whole team.
  • Java
  • Go
  • TypeScript
  • Google Cloud

Lead engineer2022 – 2025

  1. EMV terminals
  2. Payment gateway
  3. Processor

Integrated payments

A payment gateway and its EMV terminal fleet

New gateway capabilities for software platforms and their merchants, plus the EMV terminals they take payments on.

  • Microservices on AWS Lambda, KMS, EC2 and S3, from design through validation.
  • Subject-matter expertise for the platform's EMV-capable terminal fleet.
  • TypeScript
  • Node.js
  • PHP
  • AWS

Team lead2020 – 2022

  1. Client systems
  2. Payments + billing design
  3. Stripe

Consulting

Payment and billing architectures on Stripe

Payment and billing solutions for clients across many industries, designed and delivered as a Stripe-certified architect.

  • Payment solutions for clients across a variety of industries.
  • Mission-critical client deliveries, as team lead.
  • Stripe
  • Payments
  • Billing

Technical lead2025 – now

  1. Card reader
  2. Payments SDK
  3. Merchant app
  4. Acquirer

Merchant acquiring

A mobile payments SDK for merchant apps

Let merchants take card-present payments inside their own apps, on every platform they ship to.

  • SDK features designed, built, tested and documented end to end.
  • Shipped across iOS, Android and Windows.
  • iOS
  • Android
  • Java

Engineer2018 – 2020

Writing

Notes on building software that moves money

All posts RSS

Projects

Things I've built

All projects GitHub ↗
Gameplay of Pew-Pew-Pew.io: ships moving and firing in a browser arena

Shipped 2018Real-time systems

Pew-Pew-Pew.io Game

A multiplayer browser game built to see how far Socket.io could go for real-time state sync between a server and many clients.

  • Entity-component system for game logic
  • Spatial hashing keeps collision checks cheap as players join
  • Express and Socket.io server streaming state to every client
  • Node.js
  • Socket.io
  • Express
Write-upGitHub ↗