Haku Chen

Frontend Engineer

I independently own frontend development for key products in the Life Media Tech (LMT) domain, including Shinkansen ticketing, Highway Bus, and Rental Car platforms — with Shinkansen and Rental Car built from the ground up.

• Adapted the organization's monorepo strategy and CI/CD workflows to the products I own, redesigning both to accommodate differing architecture and backend integration requirements.
• Maintaining and modernizing the existing Highway Bus platform, proactively proposing architectural refactors to resolve longstanding technical debt.
• Improved mobile performance score from 36 to 85 for the Shinkansen platform through targeted optimization.
• Onboarding and mentoring 2 junior engineers (career-changers) from foundational training to independent project contribution; currently overseeing their work across 3 concurrent projects.
• Serve as a key technical advisor in weekly PM alignment sessions, translating ambiguous product requirements into actionable scope.
• Designed automated pipelines leveraging scheduled AI workflows to detect code changes via diff comparison, auto-updating documentation and test coverage.

Frontend Engineer

As a member of the Frontend Infra team, I identified a previously unaddressed gap in performance optimization and initiated the effort, working closely with a backend engineer and a PM to evaluate Web Vitals data, define actionable improvements, and prioritize the roadmap.

• Led SEO and page speed optimization initiatives, reducing FCP/LCP by 4–10 seconds and improving SEO index coverage.
• Rewrote the legacy affiliate partners SDK library, additionally migrating it to TypeScript on my own initiative; eliminated inconsistencies in affiliate ID tracking and conversion attribution.
• Implemented member authentication flow optimization across three codebases — React Native, Next.js, and React — increasing new registration conversion rate by 0.13%.

Frontend Engineer | Assistant Team Lead

Served as frontend lead for customer-facing web products, responsible for defining technology stacks, architecting scalable frontend solutions, and mentoring engineering teams.

• Promoted to Assistant Team Lead within one year, overseeing technical decision-making and cross-team coordination across 4 product teams, each led by a team lead managing 1–2 engineers.
• Took ownership of the technical interview process, assessing candidates' technical fit for the engineering team.
• Spearheaded the company's first cross-project Design System, unifying UI/UX collaboration between design and engineering teams.
• Led modernization of legacy systems from jQuery to React, improving maintainability and developer experience across diverse business sectors.

Automating performance monitoring in a monorepo and preventing quality regressions at deploy time.

Fully automated the performance check at production release, catching unintended score regressions before they ship.

Phases I owned：

Requirements / Environment setup / Design / Rollout & operations

Team：

Solo — a company-wide infrastructure improvement. CI/CD setup and DX improvement.

Environment：

Next.js / TypeScript / GitHub Actions / Turborepo / pnpm workspace

A new business line requiring integration of multiple rental car providers with inconsistent response formats, plus a scalable delivery foundation built from scratch.

Released in January 2026 and profitable from the first month, on a maintainable delivery foundation. Development is ongoing.

Phases I owned：

Tech selection / Requirements / Design / Implementation / CI/CD

Team：

4 people — 1 frontend (me), 1 backend, 2 PM. Frontend lead — architecture, environment setup, implementation.

Environment：

Next.js / TypeScript / GitHub Actions / Turborepo / pnpm workspace / Docker / Nginx / BFF

Frontend rendering optimization for a core product, aimed at improving search ranking and user experience.

Raised the mobile performance score from 36 to over 85.

Phases I owned：

Verification / Requirements / Implementation

Team：

2 people — 1 frontend (me), 1 PM. Frontend lead, owner of the performance effort.

Environment：

Next.js / TypeScript

An initiative I started myself to cut ad spend and grow organic traffic, focused on Core Web Vitals and especially FCP.

Reduced FCP/LCP by 4–10 seconds and improved SEO index coverage.

Phases I owned：

Verification / Requirements / Implementation

Team：

1 person, as a team member. Initiator and implementer.

Environment：

Next.js / TypeScript / Zustand

Migrating legacy pages page-by-page from EJS templates — where the frontend handled UI only and data binding was managed by a .NET backend — to a React multi-page architecture.

Clarified the split of responsibility between frontend and backend, improving maintainability and build performance.

Phases I owned：

Design / Implementation / Mentoring

Team：

9 people, as sub-leader. Sub-leader — work allocation, planning, environment setup, mentoring.

Environment：

React / TypeScript / Vite / Webpack / Sass / Tailwind CSS / React Query / Zustand / React Hook Form

The company's first cross-project design system, built to unify styles and UI across multiple products and to give the design team a shared component library.

The design team could work from a shared Figma component library while the frontend team implemented matching components — consistent UI/UX with substantially less duplicated code. The library was in production use before I left, and other members kept extending it.

Phases I owned：

Environment setup / Tech selection / Design / Implementation / Mentoring

Team：

3 people, as lead. Lead — initial setup, technology selection, design direction, rollout support.

Environment：

TypeScript / React / Nx / Lerna / pnpm workspace / Rollup / Jest / Cypress / ESLint / Tailwind CSS / Storybook

Maintaining and extending the flight booking product across two coexisting codebases — React and legacy jQuery — while building shared modules usable by both.

Delivered feature improvements to the React project that measurably improved the booking experience.

Phases I owned：

Implementation

Team：

1 person, as a team member. Frontend developer.

Environment：

TypeScript / React / Webpack / Redux