Senior Backend Engineer - Python AI-Driven Finance

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 Tik Tok, 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.

You’ll help design the backend foundations for T:0’s intelligent finance systems: scalable services, resilient APIs, and thoughtful data models that support agentic workflows, AI copilots, and real-time financial infrastructure.

• Build typed, production-grade APIs and services in Python using FastAPI and Pydantic.

• Develop resilient infrastructure primitives, including queues, retries, idempotency, observability, and back pressure handling, so teams can ship quickly without sacrificing reliability.

• Work at the intersection of systems and AI, building feedback loops where product data continuously improves models and models improve system behaviour.

• Ship platform foundations, including internal frameworks, SDKs, and tooling, that accelerate engineers across the organisation.

• Partner closely with ML and product teams to product ionise research-grade ideas into customer-facing systems.

• Help define the architecture of an AI-native financial stack by designing software with AI as a first-class runtime rather than bolting AI onto existing systems.

You’ll work from our San Francisco office three days a week.

• 5+ years of backend engineering experience with Python at scale.

• Deep knowledge of SQL and No
  
  SQL database design.

• Experience with distributed systems, event-driven architectures, or microservices.

• Familiarity with GCP services such as Pub/Sub, Cloud Run, Cloud SQL, Big Query, and KMS.

• Strong understanding of security and compliance best practices.

• Experience designing and operating reliable, production-grade services.

• A passion for building the backend systems that power intelligent products.

• Experience building agentic workflows, AI copilots, or AI-native products.

• Experience with financial systems, ledgers, payments, accounting, or other high-integrity domains.

• Experience building internal platforms, frameworks, SDKs, or developer tooling.

• Experience partnering closely with ML and product teams to product ionize research or prototypes.

• You're comfortable owning the roadmap yourself.

• You're comfortable making decisions with incomplete information and moving quickly anyway.

• You're excited by a category that hasn't been won yet, and want to be early enough to shape it.

• You're comfortable with ambiguity. Give you a problem, not a prescription, and you'll run with it.

• You default to action. You'd rather course-correct in motion than wait for perfect clarity.

T:0's mission is to make finance run itself. We're building an AI-native accounting platform that closes the books, reconciles, and reports continuously, so founders can stop managing their finances and start using them to run the business. The hard part isn't adding AI to accounting. It's making AI…