Senior Frontend Engineer

Location: Japan; Remote; Singapore About the role You will be a senior contributor to our frontend product experience, working across our product suite, including our self-custodial wallet interfaces, account abstraction user flows, and a growing set of web and mobile decentralized applications (dApps). As a senior frontend engineer on the team, you will help shape frontend architecture, deliver complex user-facing features, and embed performance, reliability, and usability best practices into every release. You will work closely with designers, product managers, and engineers to take features from concept to production, while contributing to improving code quality, system design, and team workflows. Key responsibilities Frontend architecture & technical contributions: Contribute to the evolution of frontend system design, patterns, and best practices. Application development: Design, build, and maintain complex, production-grade frontend applications using TypeScript and TanStack Start. State management & data orchestration: Implement and maintain scalable client-side state using Zustand and TanStack Query to ensure predictable and performant data flows. Project ownership: Own and deliver end-to-end frontend workstreams, including: Core wallet and account abstraction UX flows High-throughput, data-rich product interfaces New web and mobile dApp surfaces Testing & reliability: Contribute to and maintain Playwright-based end-to-end test suites to improve coverage and release confidence. Cross-functional collaboration: Partner with Product, Design, and Backend teams to refine requirements and deliver high-quality outcomes. Qualifications Required experience 2 ~ 4 years of experience as a frontend engineer Strong proficiency in TypeScript and modern JavaScript. Experience with TanStack Start or comparable meta-frameworks (e.g., Next.js, Remix). Solid expertise in modern React patterns, performance optimization, and frontend application design. Ability to operate independently in ambiguous, fast-paced environments. Excellent written and verbal communication skills. Nice-to-have Experience leveraging AI-assisted coding tools (Cursor, Copilot, Claude, or similar) to accelerate development. Background in web3, blockchain, or decentralized application development. Experience in startup or scale-up environments. Location and logistics East Asia preferred (Tokyo, Singapore, HongKong)