Charles Tsoi

I started at Cathay Pacific — six years as a Product Owner on their mobile app and related notification systems. During that time the app grew from roughly 10,000 to 120,000 monthly active users. That's where I learned backlog discipline, stakeholder negotiation, and how to integrate new frontends with older backends like PSS.

Six years at one company also taught me what it means to own a product across its lifecycle — not only launch, but maintain and evolve it.

• Product ownership on Cathay Pacific Mobile App — MAU ~10,000 → ~120,000 (12x)
• Defined XML/JSON structures integrating mobile frontend with legacy Passenger Service Systems (PSS)
• Helped revamp NotiFLY — migrated legacy notifications toward a modern messaging architecture

From there I moved through HKJC and Accenture. At Jockey Club, I worked on a Solace migration — moving core infrastructure from traditional REST APIs toward event-based messaging for real-time, high-concurrency betting in a regulated environment.

At Accenture, I spent more time on the architecture side — API contracts and helping teams shift from feature factories toward value-driven delivery.

• Solace migration at HKJC — traditional APIs toward event-based messaging for real-time odds
• API contracts (Swagger) reducing integration rework by ~20% (Accenture)
• Helped shift mobile squads from feature factory toward value-driven architecture

Then Apple — two years as Engineering Project Manager, including work on the docserverless edge project, which moved numerical computation from server-side to user devices. What I took from Apple wasn't only a technology — it was a bar for how carefully decisions were reviewed, dependencies mapped, and releases evidenced.

That kind of care is what I try to bring into regulated, high-stakes environments.

• docserverless — numerical computation moved from server-side to edge user devices
• Partnered on iWork backend serverless migration — architectural reviews & dependency mapping
• Helped unblock API dependencies across CoreML, UI Engineering, and QA

At Airport Authority I've been involved in product design and vendor delivery for LLM-based agents in production, vendor technical due diligence, and keeping scope honest. One example: an infrastructure monitoring agent (Power Automate + Dynatrace + ServiceNow) that reduced manual health reporting for senior management.

• Product design and vendor delivery for an LLM monitoring agent — estimated 80% reduction in manual reporting time
• Vendor technical due diligence on Microsoft ecosystem — API, security, scalability
• Delivery support on a new Insurance System — legacy mainframe to cloud migration
• Hands-on: LungLens live at lunglenshk.vercel.app — see Work page

I'm finishing my MSc in IT Management at CUHK, steering coursework toward AI and data science so I have more hands-on technical grounding behind the product and architecture work I do day to day.

Enterprise delivery experience plus formal study in data science and system design is how I try to stay useful across product, architecture, and AI initiatives.

• MSc IT Management, CUHK — focus: Data Science, AI, System Design (Expected Q1 2027)
• Certifications: PMP, PSPO I, PSM I, Solace Certified Event-Driven Architecture Practitioner
• Hands-on repos and production work keep skills current alongside formal study