Joy Kirii

Frontend Developer with 3+ years of experience building scalable, high-performance web applications using React, Next.js, Angular, and TypeScript. Proven ability to deliver end-to-end frontend solutions across diverse product domains, from e-commerce platforms to mobile-first gaming applications serving 300+ daily users. Experienced in integrating RESTful APIs, implementing state management with Zustand, and maintaining CI/CD pipelines for reliable deployments.

Strong collaborator in agile, cross-functional teams spanning design, backend, and QA, with a focus on code quality, responsive design, and technical documentation.

Frontend Developer at Usiku Entertainment Limited (2024-05 – 2026-03)

Architected and maintained a scalable, mobile-first Next.js/TypeScript application serving 300+ daily active users with fully responsive interfaces and consistent cross-browser compatibility.

• Architected and maintained a scalable, mobile-first Next.js/TypeScript application (Usiku Beats) serving 300+ daily active users, delivering fully responsive interfaces across desktop, tablet, and mobile with consistent cross-browser compatibility
• Reduced initial page load time by 40% (from 5s to 3s) by implementing lazy loading, image optimization, and efficient state management with Zustand, directly improving user retention and Core Web Vitals scores
• Designed and built a payment integration system using Xsolla API and Django REST Framework, developing checkout flows, webhook processing with idempotency, transaction logging, and multi-currency support for in-app purchases
• Developed RESTful API endpoints with JWT authentication for artist profiles and content management, collaborating with backend developers to validate endpoint contracts, resolve data formatting issues, and ensure secure API interactions
• Built an internal testing environment for level designers with rewind and fast-forward features, streamlining QA workflows and reducing level iteration time across the team
• Wrote unit and component tests using Jest and React Testing Library for critical UI features; conducted manual end-to-end, performance, and cross-platform testing using BrowserStack and physical iOS/Android devices
• Created and maintained technical documentation including component guides, environment setup procedures (Windows/macOS), and a Notion-based QA workflow with standardized bug report templates and severity classifications, improving defect traceability across frontend, backend, and design teams

Game Tester at Electronic Arts (2023-09 – 2024-04)

Delivered structured functional and localisation testing for Tales of Kenzera: Zau, identifying and documenting 100+ bugs with detailed reproduction steps and severity ratings.

• Delivered structured functional and localisation testing for Tales of Kenzera: Zau, identifying and documenting 100+ bugs with detailed reproduction steps, severity ratings, and environment specifications, meeting enterprise QA standards equivalent to Jira-based defect workflows
• Achieved a sub-2% error rate across 500+ Swahili audio lines by performing meticulous script review and communicating cultural and linguistic nuances to the development team, ensuring localisation quality across a shipped title
• Collaborated with cross-functional engineering, design, and QA teams using Jira for bug tracking and Confluence for documentation; participated in daily standups and sprint retrospectives to maintain quality alignment and timely delivery
• Validated post-fix builds across multiple platforms, confirming defect resolution and platform compliance before release, applying the same regression discipline relevant to CI/CD-driven frontend release workflows

Frontend Developer at FundizShop (2021-05 – 2022-08)

Delivered a complete UI redesign using Angular, translating Figma specifications into pixel-accurate, production-ready interfaces resulting in 25% improvement in user satisfaction scores.

• Delivered a complete UI redesign using Angular, translating Figma specifications into pixel-accurate, production-ready interfaces through iterative design collaboration, resulting in a 25% improvement in user satisfaction scores
• Built responsive, accessible interfaces using Angular component architecture with CSS Flexbox/Grid, ensuring visual consistency and design system compliance across desktop, tablet, and mobile breakpoints
• Resolved API integration issues by partnering with backend developers to validate endpoint contracts, debug data formatting inconsistencies, and optimise request/response flows for customer-facing features

MSc in Software Development – Queen's University Belfast (2022-01 – 2023-12)

Diploma in Full Stack Web Development – Moringa School (2021-01 – 2021-12)

Bachelor in Music – The Technical University of Kenya (2016-01 – 2020-12)