Senior Front-end Engineer

Paidy is Japan's pioneer and leading BNPL service company. At Paidy, we believe in creating simple, instant experiences to take the hassle out of shopping with a touch of magic.

Paidy offers instant, monthly-consolidated credit to consumers by removing hassles from payment and purchase experiences. Paidy uses proprietary models and machine learning to underwrite transactions in seconds and guarantee payments to merchants. Paidy increases revenue for merchants by reducing the number of incomplete transactions, increasing conversion rates, boosting average order values, and facilitating repeat purchases from consumers. 

Paidy has reached an agreement to join PayPal, the global payments company. Paidy will continue to operate its existing business, maintain its brand and support a wide variety of consumer wallets and marketplaces by providing convenient and innovative services.

Paidy continues to innovate to make shopping easier and more fun both online and offline. For more information, please visit http://www.paidy.com. 

We are seeking a Senior Front-end Engineer who is passionate about building AI-enhanced payment experiences. You will create intelligent user interfaces leveraging ML models for fraud detection, credit decisions, personalized recommendations, and conversational commerce, working closely with data scientists and ML engineers.

Only candidates who already hold valid working rights in Japan will be considered.

You will work with colleagues building and improving AI-powered services: 

• MyPaidy (Consumer App): Build AI-powered features like smart payment scheduling, personalized offers, fraud alerts, and intelligent spend insights
• Merchant Tools: Create dashboards with ML-driven insights on transaction patterns, fraud risk, and customer behavior
• Paidy Admin (Internal Tools): Create intelligent workflows leveraging ML models for fraud detection, credit risk assessment, and anomaly detection
• AI Features: Design and implement conversational UI, recommendation engines, predictive interfaces, and real-time ML integrations 

• Drive architectural decisions for frontend platform and AI/ML integration patterns
• Own technical design for multi-platform features serving millions of users
• Set code quality standards, review practices, and mentor mid-level engineers 
• Collaborate closely with ML/Data Science teams to productionize AI models
• Lead technical discussions with stakeholders across product, design, and infrastructure

• 6+ years of professional frontend development experience 
• 3+ years of production experience with React and React Native
• Led technical design and architecture for complex, multi-platform features
• Mentored engineers or conducted technical interviews
• Owned production systems serving 100K+ users
• CS degree, Engineering degree, or equivalent through experience 

• Experience integrating AI/ML features in production (recommendation engines, chatbots, predictive UI, fraud detection interfaces)
• Familiarity with LLM APIs (OpenAI, Anthropic, Claude, etc.) or ML model integration patterns
• Understanding of AI/ML product constraints: latency, accuracy, explainability, graceful degradation
• Ability to collaborate effectively with data scientists and ML engineers
• Experience building user interfaces that surface ML predictions in understandable, actionable ways

• Expert-level proficiency in React.js and React Native
• Deep understanding of React Native's new architecture (Fabric, TurboModules)
• Ability to leverage native APIs for deep integrations with iOS & Android platforms 
• Familiar with native build tools: XCode, Gradle, Android Studio 
• Building pixel-perfect, performant UIs across mobile platforms 

• Proficiency with TypeScript, modern React patterns (hooks, suspense, server components) 
• Experience with state management solutions (Redux, Zustand, Jotai, or similar)  
• Modern build tools and bundlers (Vite, esbuild, Turbopack, Webpack)
• Testing frameworks (Vitest, Jest, Playwright, React Testing Library) 
• Performance optimization, accessibility (a11y), and responsive design 

• Team-based software development experience across multiple stakeholders
• High bar for producing clean, maintainable, testable code
• Deep care about performance, accessibility, and API design
• Comfortable working in large codebases with multiple stakeholders
• Strong system design and architecture skills
• Product and design sense with ability to propose improvements

• Built conversational UI, chatbots, or AI-powered assistants in production
• Experience with embeddings, semantic search, RAG (Retrieval-Augmented Generation), or vector databases
• Worked with real-time ML model serving and A/B testing AI features 
• Deep familiarity with fintech, payment products, or financial services
• Experience creating B2C user experiences at scale
• Open source contributions or technical writing
• Interest in emerging AI technologies and their application to consumer products

The Paidy team will ask about your user experiences with Paidy Apps during the interview. Please download the Paidy App and try it out!

• iOS: https://apps.apple.com/jp/app/paidy/id1220373112
• Android: https://play.google.com/store/apps/details?id=com.paidy.paidy&hl=en&gl=US

For those who are not able to download Paidy App, due to the regional restrictions, please be advised that you download the similar App, such as Klarna, Afterpay, Affirm and so forth, and come up with your opinions on these applications and services.

• Always seek to beat expectations. / 期待値を超える為に常に努力する。
• Display surprising speed and resourcefulness. / 人をスピードと機知で驚かす。
• Overcome weaknesses by leveraging the strength and help of others to win. / 仲間の強みを活かしたり協力を得ることで、自身の弱みや足りない点を克服する。

• Fully support the final decision even if at times you may disagree. / たとえ意見が対立することがあったとしても、最終決定を全面的に受け入れ支持する。
• Acknowledge and gather the power of others, by communicating and collaborating with them. / 仲間の力を認めて活用し、積極的にコミュニケーションをとり、協力する。
• Show a will to own actions and go the extra mile without being asked. / 行動について強いオーナーシップを持ち、言われずとも業務を遂行しきる覚悟を持つ。

• Strive to play an integral role. / 替えの効かない役割を果たす。
• Embrace and bridge differences in perspective, language, and culture. / 異なる意見・考え方、言語と文化の架け橋になる。
• Don’t compromise - raise the bar for yourself and others. / スタンダードを上げ続けることに妥協しない。