Backend Engineer II, Billing

Airwallex3 months ago

Location

SG - Singapore

Type

Full Time

Level

Mid

Role

Backend Engineer

Posted

Dec 15, 2025

Full TimeMid

The role

Summary

Airwallex is seeking a Backend Engineer II for their Billing team to build next-generation billing platforms and financial infrastructure. The role involves designing scalable microservices, working with cross-functional teams across Singapore and Shanghai, and developing business-critical billing solutions using Java, Spring Boot, and distributed systems technologies.

What you'll do

System Architecture: Lead planning, design, and implementation of Airwallex billing engineering systems with focus on scalability and performance

Business Requirements Analysis: Collaborate with business and product teams to understand billing requirements, analyze complex scenarios, and translate them into technical solutions

Microservices Development: Design and develop billing components using company's microservice framework, ensuring proper service boundaries and communication

Complex System Design: Complete system analysis, architecture design, and core function development for complex billing and financial systems

Technology Innovation: Research and introduce innovative technologies and solutions to improve billing platform capabilities and team productivity

Technical Leadership: Establish and maintain coding standards, contribute to technical team construction and management

Cross-functional Collaboration: Work with GTPN, PA, Scale, Issuing, and Spend teams to automate end-to-end pricing and billing processes

Platform Integration: Build easy-to-integrate billing solutions that serve both internal Airwallex needs and external customer requirements

What we look for

Technical

Java Development3+ years of Core Java development experience with proficiency in Java 8, multithreading, high concurrency, IO/NIO, and network communication

Payment Systems1+ years of experience in payment platform development with understanding of financial transaction flows

Distributed SystemsExperience designing and developing large-scale distributed, high concurrency, high load, and high availability systems

Spring EcosystemProficiency in Spring Framework and Spring Boot for enterprise application development

Network ProtocolsStrong understanding of HTTP, TCP/IP protocols and REST API specifications

Build ToolsHands-on experience with Maven and Gradle for project build automation and dependency management

ContainerizationPractical experience with Docker cluster management and container deployment

Data FormatsProficiency in JSON and XML for data exchange and API development

Education

Computer Science DegreeBachelor's degree in Computer Science or related technical field

Experience

Backend Development3+ years of experience in Internet application, large financial system, or e-commerce platform development

Payment PlatformMinimum 1 year of hands-on experience in payment platform development and financial systems

System ArchitectureExperience with design patterns and architecture of complex, high-scale distributed systems

Skills

Required skills

Java 8Core programming language with advanced features like streams, lambda expressions, and concurrent programming

Spring BootPrimary framework for building production-ready microservices with embedded servers and auto-configuration

Distributed SystemsDesign and implementation of high-scale, high-availability systems with proper fault tolerance

Payment SystemsUnderstanding of billing, invoicing, and payment processing workflows in financial technology

REST APIsDesign and implementation of RESTful web services following industry best practices

DockerContainerization technology for deployment and scaling of microservices applications

System DesignArchitecture design skills for complex, scalable billing and financial platforms

Nice to have

Kotlin/ScalaModern JVM languages for functional programming and improved code expressiveness

Cloud PlatformsAWS or Alibaba Cloud experience for scalable infrastructure and managed services

NoSQL DatabasesCassandra, Redis, or other NoSQL solutions for high-performance data storage

Container OrchestrationKubernetes or Docker Swarm for managing containerized applications at scale

Frontend TechnologiesJavaScript, React, or Angular for full-stack development capabilities

Financial DomainInternational clearing, settlement, and foreign exchange transaction experience

Big DataHadoop ecosystem knowledge for processing large-scale financial data

Compensation & benefits

Benefits

Global Collaboration

Opportunity to work with international teams across 26 offices worldwide

Professional Growth

Accelerated learning environment with exposure to cutting-edge fintech technologies

Impactful Work

Contribute to building global financial platform used by over 200,000 businesses worldwide

Innovation Focus

Work with AI tools and latest technologies to solve complex financial problems

Diverse Environment

Equal opportunity workplace with commitment to diversity and inclusion

Career Development

Growth opportunities in a rapidly expanding $8 billion fintech company

Interview process

1
Application Review — Initial screening of technical qualifications, Java experience, and payment systems background
2
Technical Phone Screen — 45-minute technical discussion covering Java fundamentals, Spring Boot, distributed systems, and payment platform experience
3
System Design Interview — Design a billing/payment system focusing on scalability, high availability, and microservices architecture
4
Coding Assessment — Live coding session or take-home assignment involving Java, Spring Boot, and REST API development
5
Team Interviews — Behavioral and technical discussions with billing team members and cross-functional stakeholders
6
Final Round — Senior leadership interview focusing on cultural fit, technical leadership potential, and alignment with Airwallex values