Senior Software Engineer Backend, Billing

Airwallex; Singapore; On-site; SGD 80,000 - 120,000; Full time

Job summary

Airwallex in Singapore is seeking an experienced engineer to lead the billing platform development. You will use your Core Java expertise to design and implement complex systems and help create innovative solutions for a global audience.

The ideal candidate has more than 6 years of experience, strong knowledge in high concurrency systems, and is motivated to drive impactful projects. Join us to shape the future of global payments.

Qualifications

• 6+ years of Core Java development experience in large financial or e-commerce systems.
• Experience in payment platform development is a must.
• Proficiency in Java 8 and related technologies including multi-threading.
• Familiarity with common design patterns for large-scale systems.

Responsibilities

• Lead planning, design, and implementation of the engineering system.
• Analyze business needs and design complex systems accordingly.
• Develop components using the microservice framework.
• Introduce innovative technologies and solutions.

Skills

Core Java development

High concurrency

Microservice framework

Payment platform development

Education

Bachelor degree in computer science

Tools

Docker

Kubernetes

Cassandra

Job description

About Airwallex

Airwallex is the only unified payments and financial platform for global businesses. Powered by our unique combination of proprietary infrastructure and software, we empower over 200,000 businesses worldwide – including Brex, Rippling, Navan, Qantas, SHEIN and many more – with fully integrated solutions to manage everything from business accounts, payments, spend management and treasury, to embedded finance at a global scale.

Proudly founded in Melbourne, we have a team of over 2,200 of the brightest and most innovative people in tech across 26 offices around the globe. Valued at US$8 billion and backed by world‑leading investors including T. Rowe Price, Visa, Mastercard, Robinhood Ventures, Sequoia, Salesforce Ventures, DST Global, and Lone Pine Capital, Airwallex is leading the charge in building the global payments and financial platform of the future. If you’re ready to do the most ambitious work of your career, join us.

Attributes We Value

We hire successful builders with founder‑like energy who want real impact, accelerated learning, and true ownership. You bring strong role‑related expertise and sharp thinking, and you’re motivated by our mission and operating principles. You move fast with good judgment, dig deep with curiosity, and make decisions from first principles, balancing speed and rigor.

You’re humble and collaborative; turn zero‑to‑one ideas into real products, and you “get stuff done” end‑to‑end. You use AI to work smarter and solve problems faster. Here, you’ll tackle complex, high‑visibility problems with exceptional teammates and grow your career as we build the future of global banking. If that sounds like you, let’s build what’s next.

About the team

The Billing Team at Airwallex is at the forefront of transforming how businesses handle pricing, billing, and invoicing. Our mission is to create a seamless, scalable, and transparent billing platform that not only supports Airwallex’s growth but also empowers our customers to easily manage their billing needs.

Our team is dedicated to developing a next‑generation billing platform designed to offer flexible pricing strategies and intuitive invoicing solutions. This platform aims to be a cornerstone for businesses, enabling them to bill and get paid effortlessly. By integrating cutting‑edge technology, we ensure that our solutions are easy to adopt and integrate, providing a robust billing experience for all users.

The engineering team spans across Shanghai and Singapore, offering the chance to collaborate with cross‑functional teams around the world. Engage with various domains such as GTPN, PA, Scale, Issuing, and Spend to automate end‑to‑end pricing and billing processes. The work here is impactful, contributing to building a platform that empowers businesses globally, making a tangible difference in their operations.

What you’ll do

We envision a future where our billing platform not only supports Airwallex internally but also serves as an easy‑to‑integrate product for our customers. By joining our team, you play a crucial role in realizing this vision, working alongside talented professionals to deliver business‑critical features and solutions. Together, we will build the next‑gen billing solution that empowers businesses worldwide.

This role is based in Singapore.

Responsibilities

• Lead the planning, design, and implementation of the Airwallex engineering system.
• Work with the business/product team to deeply understand the business needs, scenarios, and subsequent development directions, complete system analysis, architecture design, and core function development, and be able to grasp the design of complex systems to ensure the quality of complex architecture.
• Design and develop components based on the company’s microservice framework.
• Introduce innovative technologies and solutions for the team.
• Responsible for the construction and management of the technical team, and establish good internal coding standards.

Who you are

We’re looking for people who meet the minimum qualifications for this role. The preferred qualifications are great to have, but are not mandatory.

Minimum qualifications

• More than 6 years of Core Java development, more than 5 years of experience in Internet application / large financial system / e‑commerce platform development.
• More than one year experience in payment platform development.
• Bachelor degree in computer science and related majors.
• Proficient in Java 8, familiar with Java multi‑threading, high concurrency, IO / NIO, network communication, etc.
• Familiar with commonly used design patterns, with experience in design and development of large‑scale distributed, high concurrency, high load, high availability systems.
• Master various common server technologies, which can optimize service response and data query, ensure various service quality, and solve the problems of high concurrency and high availability.

Preferred qualifications

• International clearing and settlement / foreign exchange transactions.
• Fluent in English.
• Cassandra / Redis / NoSQL / Hadoop.
• Kotlin / Scala / Python / Golang / R.
• Docker Swarm / Kubernetes.
• JavaScript / Angular / React / CSS3.
• Aliyun Cloud / AWS.

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.