Senior Fullstack Engineer, Scale

About Airwallex Airwallex is the AI-native financial operating system for a real-time, intelligent economy. More than 676,000 businesses, including McLaren Racing, Qantas, SHEIN, and TikTok, use us, directly or through our platform partners, to run their financial operations or build and monetize financial products of their own. We started in Melbourne in 2015 to build the infrastructure global commerce runs on. We're the regulated backbone behind global payments: not by accident, but by design. A decade plus, 85+ licenses, and a financial infrastructure spanning North America, Europe, the Middle East, and Asia-Pacific. We're co-headquartered in San Francisco and Singapore, with more than 2,300 people across 27 offices. We hire builders with founder-level energy, people who move fast with good judgment, dig in with real curiosity, and make calls from first principles rather than waiting to be told what to do. Read our operating principles to see it in full. Hiring Location: London (Hybrid Mode) Total Compensation: 140,000 to 200,000 GBP About the Team Embedded Finance Platform: Build and maintain the multi-tenant infrastructure powering companies like Rippling, Navan, Qantas, and SHEIN. You'll architect systems that aggregate requests from all platform customers, meeting enterprise-grade SLAs for availability, latency, and throughput while handling cross-data-center scenarios. Cross-Domain Product Features: Own features that require synthesizing knowledge across business, regulatory, and technical domains—areas where no single existing team has full coverage, like tax systems, compliance-driven flows, or monetization tools. Solutions Architecture: Design integrations for enterprise prospects by translating their business requirements into technical solutions. Your architectural decisions directly influence deal outcomes—from enabling multi-million dollar contracts to differentiating in competitive sales. What you'll do Build Something That Matters: Your work directly impacts how millions of people use financial services. Companies like Rippling and SHEIN rely on infrastructure you'll build. You're not just writing code—you're shaping how businesses embed finance. Grow Beyond Engineering: You'll develop expertise that extends beyond technical skills: understanding customer business models, navigating regulatory landscapes, influencing enterprise sales. This is career growth that prepares you for technical leadership, product roles, or even founding your own company. Join a World-Class Team: Work with exceptional engineers, product thinkers, and designers across the globe. At Airwallex, you'll be challenged, supported, and surrounded by people who are building something meaningful together. Minimum Qualifications Have 5+ years of software engineering experience in ReactJS & TypeScript Excel at making the right level of abstraction—balancing flexibility and simplicity in system/component design Demonstrate clean communication across technical and non-technical stakeholders Make pragmatic decisions on when to optimize for performance vs. velocity based on business impact Thrive in cross-functional environments spanning Product, Design, Compliance, and Sales Design for scale, maintainability, and production excellence Preferred qualifications: Fintech, payments, or regulated industry experience High-scale performance tuning (100k+ QPS, large user bases, strict latency SLAs) Multi-tenant SaaS or platform architecture background Proficiency with PostgreSQL, Redis, Kafka, or cloud platforms (AWS/GCP/Azure) Experience with OAuth2.0, API design, or developer documentation Cross-region deployment or data residency compliance experience Solutions engineering or customer-facing technical experience Compensation Range: £74,822 - £138,955 + bonus + RSU Applicant Safety Policy: Fraud and Third-Party Recruiters To protect you from recruitment scams, please be aware that Airwallex will not ask for bank details, sensitive ID numbers (i.e. passpo