Ronald Ho

Mastercard | Microservices, Java Spring Boot

Sydney, New South Wales, Australia

About

I build high-scale backend systems that power modern payment platforms. As a Senior Software Engineer at Mastercard, I led the design of microservices that migrated 1B+ records from on-prem infrastructure to Oracle Cloud, enabling tokenization workloads to be processed directly in the cloud and supporting over 20 million requests annually. My focus is on designing distributed systems that are reliable, scalable, and built for long-term evolution — from event-driven architecture and data migration strategies to production-ready cloud deployments. I’m particularly interested in platform modernization, fintech infrastructure, and solving complex engineering challenges at scale.

Experience

  • Mastercard (Full-time · 2 yrs 9 mos)
    • Senior Software Engineer
      Mar 2026 - Present · 4 mos

    • Software Engineer
      Oct 2023 - Mar 2026 · 2 yrs 6 mos

      Tokenization - Architected and delivered two new Java Spring Boot microservices (ATV & TVS) from the ground up, establishing automated CI/CD pipelines for PCF deployment and implementing an Axon-based event-driven architecture - Migrated existing logic for tokenization in the Mastercard Payment Gateway Service to the cloud by launching the Token Provider Interface API, enabling the seamless processing of more than 20 million tokenization requests annually - Enhanced platform security and stability by re-architecting a core cryptographic service to support seamless key rotation.

  • Software Engineer at NAB
    Jul 2022 - Oct 2023 · 1 yr 4 mos

    Treasury Applications - Built and launched 3 different NAB internal microservices; Product Pricing Proxy API, Accounts API, and Break Cost Fee API, which enabled more than 3000 daily real time risk and loan calculations of minimum lending rates for bankers to evaluate customers and make informed decisions. - Created multiple scripts to automate certificate generation and testing, allowing other team members to streamline API creation processes - Utilised AWS technologies such as EC2, Lambda, and API Gateway to build a highly scalable and fault-tolerant API.

  • Medical Receptionist at Pymble Medical & Dental Centre
    Jun 2021 - Jul 2022 · 1 yr 2 mos

    - Providing excellent administrative and clerical support in high volume medical offices - Skilled in maintaining schedules, making appointments, taking calls, and treating patients with care and respect - Developed verbal communication skills and the ability to work under a high pressure, fast-paced team environment during peak hours.

  • Waiter at Tokyo Ramen Macquarie
    Feb 2018 - Dec 2018 · 11 mos

    - Served as a friendly, hardworking, and punctual employee. - Remained punctual and professional at all times. - Assisted with recruitment and training of new employees - Maintained a clean and organized working environment to enhance productivity.