Senior Software Engineer, Spend

About Airwallex Airwallex is the AI-native financial operating system for a real-time, intelligent economy. More than 675,000 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 2,700 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. How you'll make impact You’ll build backend systems that power Spend’s financial workflows, helping businesses manage corporate cards, expenses, bills and procurement. You’ll own features end to end while shaping reliable, scalable services for complex financial data and transaction workflows. Design and build scalable, secure backend services that power Spend’s financial workflows, including corporate cards, expenses, bills and procurement. Own features end to end, from technical design and implementation through to production operation, with a focus on accuracy, reliability and compliance across financial data. Shape the long-term architecture of backend systems, APIs and distributed services that support complex, high-volume transaction workflows. Partner closely with Product, Infrastructure, Design and other Engineering teams to turn customer and business needs into reliable technical solutions. Raise the engineering bar through high-quality, testable code, strong observability and thoughtful technical mentorship. You’ll work from our Melbourne office on Monday, Thursday and Friday. What we're looking for Essentials A bachelor’s degree in Computer Science, Software Engineering or a related field. 5+ years of professional software engineering experience. Hands-on experience designing and building backend systems and APIs in production. Strong computer science fundamentals, including algorithms, data structures and distributed systems. Proficiency in at least one backend language, such as Java, Kotlin, Go or Python. Solid understanding of REST API design and backend frameworks, such as Spring Boot. Experience working with cloud infrastructure, such as AWS or GCP, and container orchestration, such as Kubernetes. A strong focus on performance, reliability, maintainability and code quality. Preferred Familiarity with observability and monitoring tools, such as Grafana, Prometheus or Splunk. You'll thrive here if You're comfortable owning the roadmap yourself. You own the outcome and you don't wait for permission to fix what's broken. You're comfortable making decisions with incomplete information and moving quickly anyway. You hold yourself to a high standard even when no one is watching. Quality and accountability aren't external expectations, they're internal ones. You're comfortable with ambiguity. Give you a problem, not a prescription, and you'll run with it. You say what you mean. You're direct, but you lead with respect. You connect dots across functions and hold the big picture without losing grip on the details. Learn more about your team The Spend team builds Airwallex's financial operating layer for modern businesses, bringing together corporate cards, expenses, bills, and procurement on top of our accounts, payments, and issuing infrastructure. We're building AI that makes real decisions about expenses, policies, and payments, aiming to get 95%+ of submissions down to one click, while every workflow still has to hold up across multi-entity businesses, currencies, and audit trails. This is a team for people who want broad ownership across product, data, and AI, while the roadmap is still being defined. If you want to build production AI for real financial workflows that directly change how businesses operate, this is where that work happens. 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. passport), or any form of payment during the application or interview process. All official communication will come from an @ airwallex.com email address. Please apply only through careers.airwallex.com or our official LinkedIn page. Airwallex does not accept unsolicited resumes from search firms/recruiters. Airwallex will not pay any fees to search firms/recruiters if a candidate is submitted by a search firm/recruiter unless an agreement has been entered into with respect to specific open position(s). Search firms/recruiters submitting resumes to Airwallex on an unsolicited basis shall be deemed to accept this condition, regardless of any other provision to the contrary. Equal opportunity Airwallex is proud to be an equal opportunity employer. We value diversity and anyone seeking employment at Airwallex is considered based on merit, qualifications, competence and talent. We don’t regard color, religion, race, national origin, sexual orientation, ancestry, citizenship, sex, marital or family status, disability, gender, or any other legally protected status when making our hiring decisions. If you have a disability or special need that requires accommodation, please let us know.