Senior Backend Engineer, Stablecoin Platform
Backend Engineer · Senior · Full Time
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Role
What you'll do.
Senior Backend Engineer leading the design and implementation of stablecoin infrastructure at Airwallex, a unicorn payments platform serving 250,000+ businesses globally. You'll architect secure blockchain systems for key management, transaction signing, and digital asset custody while integrating stablecoin infrastructure into existing FX and payment systems. This role requires 5+ years of production software development experience with proven blockchain infrastructure expertise and a deep understanding of secure financial systems architecture.
Responsibilities
- Stablecoin Infrastructure Architecture and Development: Lead the design and implementation of secure stablecoin infrastructure from the ground up, including systems for blockchain integration, transaction lifecycle management (mint, burn, transfer, reconciliation), and digital asset custody. Architect solutions that enable seamless stablecoin functionality across Airwallex's global platform.
- Secure Key Management and Cryptographic Systems: Design and implement production-grade systems for private key handling, transaction signing, gas fee management, and blockchain integration. Establish robust operational controls and security protocols that meet enterprise financial standards and regulatory compliance requirements.
- Multi-Chain Ledgering and Balance Reconciliation: Own the development of internal ledgering systems that accurately track balances across multiple blockchain networks and token types. Build reconciliation mechanisms that maintain data integrity and ensure real-time visibility into stablecoin holdings and transactions.
- FX and Payment System Integration: Integrate stablecoin infrastructure seamlessly into Airwallex's existing foreign exchange and payment systems, enabling transparent conversion between fiat currencies and stablecoins. Ensure integration maintains system stability without introducing regressions or technical debt in legacy or distributed environments.
- Production Code Development and Code Review: Write, review, and deploy production-grade backend code following object-oriented design principles and best practices. Maintain high code quality standards through comprehensive testing, documentation, and peer review processes in a collaborative engineering environment.
- Cross-Functional Collaboration and Delivery: Collaborate effectively with product, infrastructure, and compliance teams to deliver reliable, auditable financial services. Communicate complex technical concepts to non-technical stakeholders and work end-to-end to solve high-visibility problems with exceptional teammates.
Qualifications
What we look for.
Technical
Strongly Typed Language Expertise
5+ years of production software development with deep expertise in at least one strongly typed programming language such as Kotlin, Java, C#, C++, or Rust. Strong proficiency in object-oriented design patterns, SOLID principles, and enterprise-grade architecture.
Blockchain and Web3 Infrastructure
Proven hands-on experience building and integrating blockchain infrastructure components including smart contract interfaces, wallet systems, transaction signing flows, key management systems, and on-chain liquidity mechanisms into financial platforms.
Secure System Design
Deep understanding of cryptographic principles, private key management, encryption protocols, transaction signing mechanisms, and operational security controls. Experience architecting systems that handle sensitive financial data and meet compliance and auditability standards.
Legacy System Integration
Demonstrated expertise integrating new systems into legacy or distributed environments while maintaining stability, backward compatibility, and preventing regressions. Experience with careful rollout strategies and monitoring in production financial systems.
Database and Ledger Systems
Experience designing and implementing ledger systems, transaction reconciliation systems, and distributed databases. Knowledge of eventual consistency, ACID compliance, and audit trail requirements in financial contexts.
Education
Computer Science or Engineering Degree
Bachelor's degree in Computer Science, Software Engineering, Mathematics, or related technical field. Equivalent practical experience demonstrating strong fundamentals in algorithms, data structures, and system design may substitute.
Experience
Senior-Level Backend Development
Minimum 5+ years of professional backend software engineering experience building production systems at scale. Track record of architecting and implementing complex systems end-to-end with ownership and technical leadership.
Blockchain Infrastructure Integration
Proven experience building or integrating blockchain infrastructure (wallets, transaction flows, key management, etc.) into larger financial or business systems. Understanding of blockchain consensus mechanisms, network topology, and transaction finality.
Financial Systems Development
Experience working in fintech, payments, FX, treasury, or financial infrastructure environments is valuable. Understanding of payment flows, currency conversion, settlement, and regulatory requirements in financial services is beneficial.
Distributed Systems and High-Reliability Engineering
Experience building and maintaining highly available, distributed systems in production environments. Familiarity with observability, monitoring, incident response, and operational excellence in mission-critical infrastructure.
Skills
Required
Backend Development
Production-grade backend engineering with expertise in service architecture, API design, and system scalability
Object-Oriented Design
Deep knowledge of OOP principles, design patterns, and enterprise architecture patterns
Blockchain/Web3 Architecture
Hands-on experience with blockchain networks, smart contract integration, and distributed ledger systems
Cryptography and Security
Understanding of cryptographic principles, key management, secure communication, and threat modeling
Financial Systems Knowledge
Understanding of payment flows, transaction settlement, currency conversion, and regulatory compliance in fintech
System Integration
Experience integrating complex systems into production environments with minimal downtime and regression risk
Technical Communication
Ability to articulate complex technical concepts clearly to both technical and non-technical stakeholders
Preferred
FX and Payments Infrastructure
Nice to havePrior experience building or maintaining foreign exchange, payments, or treasury infrastructure systems
Stablecoin or Digital Asset Experience
Nice to haveHands-on experience with stablecoins, digital asset management, or tokenization platforms
Python Development
Nice to haveProficiency in Python for scripting, tooling, or backend services (supplementary to strongly typed language experience)
DevOps and Infrastructure
Nice to haveFamiliarity with cloud platforms, containerization, CI/CD pipelines, and infrastructure-as-code practices
Database Optimization
Nice to haveExperience with relational and non-relational database design, query optimization, and scaling strategies
Tech stack
Languages
Frameworks
Databases
Tools
Other
Compensation
Pay and benefits.
Base·SGD 140,000 – 200,000
Equity·Stock options
Benefits
Global Impact and Scale
Work on infrastructure serving over 250,000 businesses worldwide including industry leaders like Brex, Rippling, Qantas, and SHEIN. Your code directly enables commerce at a global scale.
Cutting-Edge Technology
Lead the charge in building next-generation stablecoin and blockchain infrastructure. Work with emerging Web3 technologies and shape the future of global financial systems.
High Autonomy and Ownership
Take end-to-end ownership of high-impact projects. You'll have the autonomy to make architectural decisions and see your ideas shipped to production serving millions of transactions.
Learning and Career Growth
Work alongside exceptional engineers and product leaders in a fast-paced fintech environment. Accelerated learning opportunities in blockchain, payments infrastructure, and global financial systems.
Competitive Compensation
Competitive salary package commensurate with Singapore market rates for senior backend engineers in fintech. Equity participation in a US$11 billion unicorn backed by world-leading investors.
Founder-Like Environment
Join a company culture that values builder mentality, first-principles thinking, and rapid execution. Collaborate with founders and leaders who've built multiple successful ventures.
Global Team and Offices
Work with over 2,300 talented engineers and professionals across 27 offices globally. Exposure to diverse perspectives and international best practices in fintech.
Process
Interview steps.
- 01
Initial Screening Call
30-minute conversation with a recruiter to discuss your background, experience with blockchain and financial systems, and alignment with the role. Opportunity to ask questions about the team and Airwallex.
- 02
Technical Assessment
Coding interview assessing your proficiency in a strongly typed language (Kotlin, Java, C++, or Rust) and system design thinking. Focus on object-oriented design, data structures, and solving real backend engineering problems.
- 03
Blockchain and Systems Deep Dive
Technical discussion with the hiring engineering manager on blockchain infrastructure, key management systems, transaction signing, and how you'd architect stablecoin integration. Bring examples of blockchain systems you've built or integrated.
- 04
System Design Interview
Collaborative 60-minute session designing a distributed financial system. Discuss tradeoffs in architecture, scalability, reliability, and security. You'll be assessed on problem-solving approach, communication, and ability to iterate on feedback.
- 05
Team Fit and Values Conversation
Discussion with team members and/or engineering leaders about collaboration style, decision-making approach, and alignment with Airwallex's founder-like energy and operating principles.
- 06
Final Round - Leadership Discussion
Conversation with senior leadership or the Financial Markets team lead to discuss long-term vision for stablecoin infrastructure, growth opportunities, and how you'd approach high-impact projects.
Full posting
Original listing.
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 250,000 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 2,300 of the brightest and most innovative people in tech across 27 offices around the globe. Valued at US$11 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 Financial Markets team is responsible for Airwallex’s core FX and liquidity infrastructure. We’re now expanding into building the stablecoin infrastructure that will enable both customers and internal systems to buy, hold, send, and settle with tokenised currency globally. This includes support for near-instant global payments, on-chain liquidity, and seamless conversion between fiat and stablecoin balances. We’re building stablecoins into the core of Airwallex’s infrastructure, so they function as seamlessly as any fiat currency across our global platform.
We're seeking a skilled developer to take a leading role in advancing our initiatives. Someone who can both architect and build robust, reliable systems and tackle the challenges of blockchain integration, digital asset custody, and global payments infrastructure.
What You’ll Do
Be part of a high-impact engineering team building stablecoin infrastructure from the ground up.
Design and implement secure systems for key management, transaction signing, gas fee management, and blockchain integration
Own services that manage the full lifecycle of stablecoin transactions mint, burn, transfer, reconciliation
Build internal ledgering systems that track balances across multiple chains and token types
Integrate stablecoin infrastructure into Airwallex’s existing FX and payment systems, enabling seamless conversion between any supported currency and stablecoins
Write, review, and ship production code
Collaborate with product, infrastructure, and compliance teams to deliver reliable and auditable services
Responsibilities
Minimum qualifications:
A highly experienced engineer (5+ years) with deep expertise in object-oriented design and production-grade software development, including at least one strongly typed language (e.g. Kotlin, Java, C#, C++, Rust); Python experience is useful but not sufficient on its own
Proven experience building and integrating blockchain infrastructure (wallets, transaction flows, key management, etc.) into larger financial systems
Experienced in integrating new systems into legacy or distributed environments without introducing instability or regressions.
Strong grasp of secure system design, particularly around private key handling, signing, encryption, and operational controls
Able to quickly pick up unfamiliar tools or frameworks when needed and adjust to changing technical priorities.
Clear communicator who works well across engineering, product, and non-technical teams
Preferred qualifications:
Experience in FX, payments, or financial infrastructure is useful but not required
#Singapore
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.
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