Career Journey

Professional Experience

Architecting high-scale enterprise software, GenAI automation pipelines, and native mobile apps.

June 2025 — Present

Fullstack Developer

Visa Inc
Singapore
Visa Inc Logo
  • Maintained and drove the success of the high-impact Visa Test Portal, serving 2,200+ monthly user subscriptions across major banking clients and merchants and facilitating 255,000+ transactions.
  • Led end-to-end Generative AI development to automate GTLIG document analysis, slashing test case creation time by 98% (from 8,000 to 50 man-hours) for 1,000+ page technical documentation.
  • Architected and deployed a custom RAG pipeline, delivering the first live demo within 5 months of initial commit to accelerate time-to-market.
May 2024 — August 2024

Software Developer Intern

Visa Inc
Singapore
Visa Inc Logo
  • Engineered key enhancements to the Visa Test Portal’s UI/UX, directly improving usability and operational efficiency for an expansive global client network.
  • Expedited product delivery cycles by diagnosing and resolving 9+ critical production defects within a single sprint, bolstering deployment stability and platform reliability.
  • Championed collaborative innovation by leading a cross-functional team spanning Singapore and India to secure 1st place in the APAC Case Competition, demonstrating excellence in strategic technical problem-solving.
May 2023 — July 2023

Security & Architecture Intern

Sumitomo Mitsui Banking Corp
Singapore
Sumitomo Mitsui Banking Corp Logo
  • Engineered automated patch deployment for Virtual Machines using Jenkins pipelines (Shell/PowerShell), reducing manual effort by ~70%.
  • Led evaluation of critical Proof of Concepts (JWT Caching, mTLS) and executed testing for 10+ APIs across cloud infrastructure.
  • Authored enterprise Cloud Operation Guidelines across 10+ cloud APIs, creating a standardized onboarding knowledge base that reduced engineer ramp-up time.
January 2023 — April 2023

Mobile Development Intern

Align Technology
Singapore
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  • Collaborated with regional leadership to execute feature roadmaps for the Insight App, optimizing operational capabilities across the APAC region.
  • Developed a predictive Machine Learning model for quarterly sales forecasting, enhancing resource allocation accuracy and strategic planning.
February 2021 — December 2022

IT Support & QA Specialist

ComfortDelGro
Singapore
ComfortDelGro Logo
  • Developed automated computer deployment processes using PowerShell, driving a 70% efficiency gain.
  • Conducted Quality Assurance testing for mobile applications, resolving 30+ critical bugs and performing API troubleshooting using Burp Suite.

Joel Tan

Software Engineer • Fullstack & GenAI