GolfJoy engineering case study | Yuan Zhou Canonical page: https://yuanzhou.dev/work/golfjoy Resume: https://yuanzhou.dev/resume I was the project lead and sole developer for the GolfJoy software described here, using AI tools while retaining responsibility for implementation, integrations, testing, and delivery. 2026 ยท Completed project-based delivery FIVE DOCUMENTED DELIVERIES - GolfJoy China official website - GolfJoy U.S. official website - GolfJoy Play - GolfJoy Play native application - GolfJoy Content Management System (CMS) DELIVERY COORDINATION I coordinated delivery with content operations, venue operators, and field support, turning their requirements into implementation decisions, acceptance checks, and production releases. Make the CMS match the operator's work. Collaborators: China content operations Problem: Editors could not reliably change the product information customers saw. The CMS fields did not match the pages, and code could override published content. My decisions: I translated operator feedback into page-aligned editing, made published CMS content authoritative, and kept pricing behind confirmation and audit checks. Draft preview and revert were part of acceptance testing. Delivery result: Released the product and About-page changes to China production on September 15, 2026, with the published content checked against the live pages. Coordinate an eight-bay venue rollout. Collaborators: New Zealand venue operator, field support, and device vendor Problem: An operating venue needed its local booking rules, physical bays, and device registrations to agree before moving to the production platform. My decisions: I turned local requirements into configuration and acceptance checks, and owned the technical decisions and release. Field support coordinated with the vendor to resolve a device-registration gap and verify physical behavior. Delivery result: Completed the production cutover on August 26, 2026, with booking records reconciled. The rollout used controlled write freezes and a fallback path, with further physical checks tracked separately. ENGINEERING CONTRIBUTIONS CMS & platform architecture Built Next.js/TypeScript storefronts and a Payload CMS/PostgreSQL content system. Translated China operations feedback into page-aligned editing, draft previews, and audited price updates, then carried the changes through testing and production rollout. China commerce & reliable releases Delivered the China storefront with customer accounts, payments, and regional content management. Designed Ed25519-signed CMS snapshots, atomic deployments, and rollback so releases could run without a live cross-border database connection. U.S. commerce & AI guidance Built the U.S. commerce experience to help buyers compare products and configure simulators through guided selection and a 3D room builder. Integrated Shopify checkout and webhook reconciliation; grounded AI guidance in approved sources with response guardrails and human handoff. GolfJoy Play | Venue operations Built a venue platform for bookings, memberships, payments, refunds, waivers, device ingestion, and access control. Led technical decisions and an eight-bay New Zealand rollout with the operator and field support, aligning local rules, vendor device registration, and acceptance checks. Enforced tenant-scoped permissions and server-side pricing. GolfJoy Play | Native sensor app Released the Android app on Google Play with 11 interface languages, live shot metrics, practice history, landscape displays, placement guidance, and English shot readout. Connected Bluetooth discovery and Wi-Fi sensor data through Java/Swift bridges and a shared C++ protocol core. WORKING METHOD I use AI tools to accelerate implementation while retaining responsibility for problem decomposition, architecture, code review, testing, integrations, and release decisions. PUBLIC EVIDENCE The company identifies Yuan Zhou as the primary project lead and sole developer responsible for technical implementation and production deployment of the five projects named in this letter. Company accomplishment letter: https://yuanzhou.dev/golfjoy/project-accomplishment-letter-2026-10-09.jpg Product gallery & engineering case study: https://yuanzhou.dev/work/golfjoy Android app on Google Play: https://play.google.com/store/apps/details?id=com.golfjoy.play Company-confirmed delivery: https://yuanzhou.dev/golfjoy/project-accomplishment-letter-2026-10-09.jpg China production engineering credit: https://golfjoy.com/cn/humans.txt Independent release-gate reference implementation: https://yuanzhou.dev/lab/release-gate The implementation account is by Yuan Zhou. Product and source-code ownership remains with the respective owners. No employer source code, internal records, or private customer data is reproduced here.