Hi, I'm Joel Tan! I'm a software engineer and Fullstack Developer at Visa Inc in Singapore, with a BSc in Information Systems from Singapore Management University (SMU).

I specialize in building high-performance web applications, payments architecture, and developer tooling across Python, React, TypeScript, and Docker.

Engineering & Career Background

  • Fullstack Developer @ Visa Inc (2024 – Present): Architected an end-to-end GenAI testing suite reducing manual test creation effort from 8,000 to 50 man-hours (98% efficiency gain). Designed custom Retrieval-Augmented Generation (RAG) pipelines for technical documentation and built real-time transaction log (GTLIG) dashboards.
  • Security & Architecture Intern @ SMBC (2023): Engineered automated patch management pipelines for Azure VMs with Jenkins & Shell scripts (70% overhead reduction) and evaluated JWT Caching & mTLS for 10+ critical banking APIs.
  • Mobile Development Intern @ Align Technology (2023): Developed cross-platform React Native features for the APAC market and built ML predictive revenue models in Python.

Featured Projects

  • LessonsToPayment: A 9-part deep-dive technical series demystifying the payments industry, ISO 8583 standards, 4-party authorization flows, and real-time fraud scoring.
  • Blood Bank Tracker: An automated Python & GitHub Actions scraper monitoring national blood stock levels from the Red Cross to encourage timely blood donations.
  • ESDeezknee: Microservices theme park enterprise platform powered by Python, Docker, RabbitMQ, Kong, and Stripe.

Writing & Philosophy

I believe in learning in public and breaking down complex engineering systems into intuitive, high-signal essays. When I'm not coding or writing about payments architecture, you can find me exploring new tech stacks or competing in hackathons.

Connect

Feel free to explore my work on GitHub, connect on LinkedIn, or subscribe to the RSS Feed.