Heydar
Rzayev.

Platform, payment, and tooling systems for HTML5 games with millions of monthly players.

• Delivered admin panels in React, TypeScript, and Ant Design used daily by 30+ product, live-ops, and support staff to manage players, offers, and game configuration without code deploys.
• Built a real-time metrics dashboard processing 600M+ database rows per day, designing the data model, indexing, and query architecture behind it.
• Introduced and drove team-wide adoption of an AI-assisted engineering workflow built on Claude Code: designed it, presented it on-site, and wrote the repository-level standards that let AI agents work reliably in existing codebases.
• Developed internal Firebase / Firestore wrapper libraries adopted across 20+ game titles, cutting per-game integration from ~3 days to under half a day.
• Shipped the Guest Purchase flow, removing account creation from checkout and lifting IAP conversion ~15%.
• Identified and mitigated a critical vulnerability in the Xsolla payment integration, then refactored it into a reusable pattern now standard across upcoming titles.
• Built a Yeoman-based scaffolding CLI generating production-ready projects with CI/CD, linting, and SDK wiring, cutting setup from ~2 days to under 15 minutes.

• TypeScript
• React
• Ant Design
• Node.js
• Firebase
• Firestore
• Cloud Functions
• AWS
• Docker
• GitLab CI/CD
• Claude Code

Building Information Modeling (BIM) platform for planning and automating construction projects.

• Built interactive 3D BIM model viewers with Three.js and Angular 17, rendering models with 500K+ elements at a stable 60 fps through geometry instancing, frustum culling, and lazy loading.
• Migrated component state to Angular Signals and computed properties, cutting change-detection cycles ~40% on large models.
• Designed the RxJS data layer for the Python / MongoDB backend, handling async streams, request cancellation, and retries for 15+ REST endpoints.
• Introduced Playwright end-to-end tests covering ~80% of critical user journeys and wired them into CI, reducing regressions reaching production by ~50%.

• Angular 15–17
• TypeScript
• RxJS
• Three.js
• Python
• MongoDB
• Playwright
• Webpack

Digital freight marketplace (DHL Group) connecting shippers and carriers across Europe and the Middle East.

• Owned the product backlog for a squad of 8 engineers, running sprint ceremonies and raising sprint predictability to ~90%.
• Translated business requirements into user stories with clear acceptance criteria in JIRA and Confluence, cutting mid-sprint scope changes and rework.
• Worked hands-on with QA on debugging and triaging defects, reducing average bug turnaround time by ~30%.
• Wrote Jest unit tests for frontend features alongside the engineering team, laying the groundwork for my move into engineering.

• JIRA
• Confluence
• Jest
• GitLab
• Figma
• Aha!