Web3 React Jobs in Japan

Binance is a leading global blockchain ecosystem behind the world’s largest cryptocurrency exchange by trading volume and registered users. We are trusted by 300+ million people in 100+ countries for our industry-leading security, user fund transparency, trading engine speed, deep liquidity, and an unmatched portfolio of digital-asset products. Binance offerings range from trading and finance to education, research, payments, institutional services, Web3 features, and more. We leverage the power of digital assets and blockchain to build an inclusive financial ecosystem to advance the freedom of money and improve financial access for people around the world.

About the Team 

The Identity & Security team owns the front door to Binance. We build and operate the registration, login, and account security experience used by every one of our 300M+ users — social login, OAuth and third-party authorization, multi-factor authentication, passkeys and FIDO2, device management, account activity, and account closure.

We are currently building an in-house AI facial recognition security product for KYC verification and user safety, replacing our existing third-party vendor solution. This is a to-C product serving hundreds of millions of users, directly impacting account security and identity verification experience at scale.

Our work sits where three forces meet: enormous scale, strict security and regulatory constraints, and the reality that one extra verification step can block an attacker or lock out a legitimate user. We ship across web, mobile mini programs, and in-app webviews, and we publish the shared authentication libraries and SDKs that the rest of Binance builds on.

Responsibilities

• Design, develop, and maintain the login, registration, and account security applications across web and mobile clients
• Build the in-house AI facial recognition security product end to end — KYC verification, liveness detection, face matching — replacing the existing third-party vendor solution
• Build authentication capabilities end to end: passkeys / FIDO2 (WebAuthn), authenticator apps, security keys, SMS and email verification, and biometric flows
• Own the multi-factor authentication orchestration layer — verification strategy, step-up logic, and user-level customization — balancing security strength against completion rate with measurable outcomes
• Collaborate closely with the AI algorithm team to integrate facial recognition, liveness detection, and other AI model capabilities into the product frontend and backend, building high-concurrency, low-latency online inference services
• Maintain and evolve the shared security component and logic libraries consumed by multiple product applications, and the authentication SDKs published to teams across the company; take responsibility for bundle size, initialization behavior, and backward compatibility
• Develop and operate the Node.js server-side layer: server-side rendering, route-level authentication guards, session validation and redirects, localized routing, and first-paint performance
• Build and refine the BFF layer — aggregating upstream security services and turning raw error codes into results the frontend can consume and users can act on
• Implement platform-specific behavior for web, mini program, and low-end device targets while keeping shared and platform-specific code cleanly separated
• Drive engineering quality: unit and end-to-end test coverage, instrumentation and observability, build and local development experience
• Use funnel and event data to find drop-off in login and verification flows, and drive optimization from evidence rather than intuition
• Collaborate closely with product, design, risk, customer support, backend, iOS, and Android teams; independently own the end-to-end design and delivery of a sub-domain such as passkeys, MFA orchestration, or facial recognition verification

Minimum qualifications

• Bachelor's or Master's degree in Computer Science, Engineering, or equivalent industry experience
• 3–8 years of frontend or full stack engineering experience, including consumer-facing products taken from zero to one or evolved over multiple years
• Strong web fundamentals: HTML, CSS, JavaScript/TypeScript, browser rendering, networking, caching, and performance optimization
• Deep proficiency in React 18+ and TypeScript, with solid command of state management, data-fetching patterns, and complex multi-step form and flow orchestration
• Production Node.js experience: server-side rendering or isomorphic applications, BFF layering, API aggregation and caching, and the ability to independently debug server-side runtime issues
• A clear methodology for modeling complex flows — authentication and verification are highly branched, stateful, interruptible, and resumable, and need to be abstracted into testable, reusable models rather than nested conditionals
• Solid engineering practice: modular architecture, component design, unit and E2E testing, CI/CD, and responsible judgment on breaking changes to shared libraries (versioning, staged rollout, rollback)
• Proficient with AI-assisted development tools (Cursor / Claude Code / Copilot, etc.) with practical experience incorporating them into daily development workflows
• Strong analytical and troubleshooting skills for diagnosing production issues, compatibility problems, and performance bottlenecks independently
• Fluent in Mandarin, able to collaborate effectively with China-based teams
• Effective communication in English within a distributed, cross-timezone, multi-team environment

Nice to have

• Experience at AI / computer vision companies in business-side frontend or fullstack development
• Hands-on experience in identity and authentication: WebAuthn / FIDO2 / passkeys, TOTP, OAuth 2.0 / OIDC, JWT and token lifecycle management, risk engines, or device fingerprinting
• Experience building to-C security products, identity verification, or KYC-related products
• Experience replacing third-party vendor solutions with in-house systems, ensuring smooth business transition
• Knowledge of AI model engineering: model inference services, RAG systems, AI Agent architecture, or computer vision model integration
• Cross-platform experience: mini programs, hybrid applications, and in-app webview bridging and debugging
• Experience shipping shared component libraries or SDKs to third-party consumers — multi-entry bundling, tree-shaking, semantic versioning, and integration support
• Internationalization and localization at scale: date and number formatting, RTL, and regional compliance differences
• Background in finance, payments, or another high-security domain, with an understanding of the product trade-offs compliance imposes
• Experience with monitoring and alerting, staged rollout, and A/B experimentation
• Docker / Kubernetes / CI-CD pipeline experience

Why Binance• Shape the future with the world’s leading blockchain ecosystem• Collaborate with world-class talent in a user-centric global organization with a flat structure• Tackle unique, fast-paced projects with autonomy in an innovative environment• Thrive in a results-driven workplace with opportunities for career growth and continuous learning• Competitive salary and company benefits• Work-from-home arrangement (the arrangement may vary depending on the work nature of the business team)Binance is committed to being an equal opportunity employer. We believe that having a diverse workforce is fundamental to our success.By submitting a job application, you confirm that you have read and agree to our Candidate Privacy Notice.We may use artificial intelligence (AI) tools to support parts of the hiring process, such as reviewing applications, analyzing resumes, or assessing responses and identifying potential inconsistencies or verification signals in application materials based on available information. These tools assist our recruitment team but do not replace human judgment. Final hiring decisions are ultimately made by humans. If you would like more information about how your data is processed, please contact us.