Senior Software Engineer - API

Mō te tūranga | About the Role

At Westpac NZ, we are focused on creating simple, safe and seamless banking experiences for our customers. Within our Payments Engineering team, you will play a key role in shaping how APIs enable secure and real time payment experiences across our digital ecosystem. 

As a Senior Software Engineer, you will design, build and evolve Java based API services that support critical payment flows. You will work closely with product, platform and engineering teams, contributing to architecture decisions and helping uplift API first capability across the payment’s domain. 

 You’ll be joining at a point where a lot is happening in parallel — new mobile and web experiences, shifts in how we work, and ongoing architectural change across Westpac. This requires strong adaptability, a pragmatic mindset, and the ability to deliver value in the face of ambiguity and evolving priorities. 

You will join a supportive, collaborative squad operating in a fast-paced delivery environment that values sharing knowledge, continuous learning, and working together. Balancing speed, quality, and risk is critical. You will play a key role in helping teams navigate this complexity while maintaining customer focus.

• Design, build and maintain mobile applications that deliver meaningful customer experiences in a fast-paced environment with evolving requirements and tight delivery timelines. 
• Collaborate with architecture and wider Payments team to align on and implement architectural changes while continuing to deliver new customer features. 
• Contribute to architecture and design decisions across API and integration layers  
• Develop high quality backend services using Java and modern frameworks  
• Collaborate with cross functional teams to deliver secure and reliable payment solutions  
• Drive quality engineering practices including testing, monitoring and performance optimisation  
• Support continuous improvement of systems, tooling and engineering practices  
• Mentor and support engineers, contributing to a strong and inclusive team environment  
• Ensure solutions meet regulatory, security and compliance requirements 

Nā tāu rourou | What will you bring?

• 7+ years of experience in software engineering, with strong backend development expertise in Java.  
• Strong collaboration skill, with working across teams to align on shared goals, dependences and technical direction. 
• Experience working in complex environment where multiple initiatives are delivered in parallel. 
• Hands on experience building REST APIs and microservices architectures.  
• Experience working with API platforms and integration patterns.  
• Experience with frameworks such as Spring Boot or similar. 
• Proven experience designing and delivering scalable integration solutions, with a solid understanding of system design and architecture principles. 
• Strong capability across testing, debugging and quality engineering practices, with experience in building reliable and maintainable services. 
• Experience with CI CD and DevOps practices, including modern delivery pipelines and cloud-based platforms. 
• Strong problem-solving skills, with the ability to simplify complex integration challenges and deliver practical, customer focused outcomes. 
• Able to balance ideal engineering outcomes with delivery constraints and business outcomes. 
• Strong communication and collaboration skills, with a team focused mindset, and integrates AI effectively into engineering workflows to improve quality and efficiency, demonstrates strong judgement on appropriate use, and coaches others on responsible AI practices. 

Westpac Hei Wāhi Mahi | Working at Westpac

• In addition to immersing yourself in a supportive team environment, you'll receive some great job perks and benefits including:
• 4 weeks standard holiday + 5 additional days of wellbeing leave to support you to be your best
• Additional purchased leave options up to 4 weeks per year
• Banking benefits, insurance discounts and superannuation scheme
• Growth and development – we provide opportunities for development and promote internal mobility
• Recognition - we recognise and reward our star performers
• School holiday subsidy - help you balance work and family during school holiday
• 2 Volunteer days per year

Ko mātou tēnei | Our Organisation
At Westpac, we’re working together to build a fairer and stronger New Zealand for our people, customers, and communities. For over 160 years we’ve been driven by our purpose to Create Better Futures Together.

What makes us unique are the incredible people we’re lucky enough to have walk through our doors every day. The giant ‘W’ on our building doesn’t just stand for Westpac – it says, double you. We’re a place that values, rewards and recognises individuality. Where you can be your whole self, your true self, and your best self. We’re recognised as a place where talent is developed, where passions are fuelled and where ambitions of all shapes and sizes thrive. And it all starts with you!

Tono mai ināianei! | Apply Now!

Apply today with your CV and Cover Letter. 

The people of Aotearoa, New Zealand hail from many cultures and backgrounds. At Westpac New Zealand, we draw on this enormous talent pool to cultivate a team rich in ability and empowered to reach its full potential. Our aim is to be brave challengers, celebrating our differences and relentlessly advocating for our customers. It starts with us – we believe that when we care deeply and do our best for our people, they’ll do their best for our customers. We encourage people from all walks of life to apply, including those who are neurodiverse, have chronic health conditions or disabilities – your attitude and passion are as important to us as your experience, qualifications and capabilities. 

Mahi tahi tātou, kaha ake tātou | Together Greater

Applications close:

24 June 2026