Frontend engineering with product-level judgment.

Enterprise SaaS and real-time platforms for international clients in Japan and Korea, plus FPT in-house products.

• Led a five-person frontend team for Jinjer Admin, an enterprise HR platform serving 100+ customers in Japan, owning employee management, approval workflows, and the frontend permission layer for role-based access control.
• Reduced the initial JavaScript payload by 35% (1.4 MB to 910 KB) through route-level code splitting aligned with RBAC route boundaries, improving LCP by 1.2s.
• Created reusable shared components and custom React hooks for recurring HR workflows, reducing duplicated logic across employee management and approval features.
• Restructured employee management and approval workflows into feature modules with their own business logic, API layer, and state while keeping shared UI components separate.
• Introduced test gates on critical paths with 90% coverage using Vitest, React Testing Library, and Cypress; production regressions fell by approximately 25% over eight sprints.
• Established frontend standards across code review, component RFCs, accessibility, and testing, and mentored two junior engineers to independent feature ownership within six months.
• Built a high-frequency rendering pipeline for an FPT in-house monitoring dashboard processing nearly 5,000 WebSocket events per minute, sustaining 58-60 FPS with INP below 120ms under burst load.
• Improved a 2,000-node React and Konva floor map for LGCNS, increasing sustained frame rate from 30 to 60 FPS and reducing React commit time by 40%.