Senior Developer - Cards & Merchant APIs

Worker Type:

Permanent

Here at BNZ, it's about more than just banking. We work together in an agile, energising environment to create innovative solutions through our promise "If you can imagine a better future, let's find a way."

We support wellbeing, flexible working and have a generous leave offering. There is the opportunity for growth, learning and career development. No two days are the same.

We have an exciting opportunity for a Senior Developer to join our Cards & Merchants team and help design, build, and support secure, resilient APIs and integration services that improve reliability and customer outcomes. 

Mō te Tūranga | About the Role 

We sat down with our Engineering Lead, and they let us know the following about the role. 

What are 5 day-to-day tasks the person in this role will complete? 

• Deliver complex API features end to end: Design, build, test, deploy, and support complex features and services across our Cards API and enterprise integration estate, balancing delivery speed with quality, reliability, and long-term maintainability. 

• Build secure and resilient API solutions: Develop enterprise-grade Java and Spring Boot services, create and implement RESTful API contracts, and apply appropriate authentication, error handling, data mapping, and integration patterns. 

• Own quality, risk, and production readiness: Embed automated testing, secure coding, observability, and operational readiness into delivery. Identify technical risks early, contribute to incident resolution and root-cause analysis, and improve services based on production learnings. 

• Solve complex technical problems and improve efficiency: Navigate ambiguous requirements, break down complex problems, assess trade-offs, and propose practical solutions that align with architecture standards and the needs of interconnected Cards and Merchant systems. Use AI tools to accelerate analysis, development, testing, documentation, and problem-solving, while identifying opportunities to simplify team processes and improve delivery outcomes. 

• Collaborate, influence, and grow others: Work closely with product, architecture, engineering, testing, platform, and security stakeholders. Contribute constructively to technical decisions, review code and designs, and mentor developers through pairing, feedback, and knowledge sharing. 

What is the team culture and environment like? 

Across BNZ we're a collaborative bunch who value open, honest conversations and continuous improvement. Everyone has a strong sense of ownership over the customer experience, from keeping services running smoothly to finding ways to make them better. We're big on learning, sharing what we know, and staying curious. 

What is the most exciting thing about this opportunity? 

Cards & Merchants is uplifting its API capability, creating an opportunity to build the reusable, standardised, and reliable services that will support Cards, Merchant, and enterprise integration outcomes for years to come. You'll combine hands-on engineering with meaningful technical influence in a high-impact environment where the quality of the APIs you deliver directly affects customers and teams across BNZ. 

What is the most challenging thing about this opportunity? 

You'll be delivering change within a complex integration landscape while also helping maintain and improve live services. Success requires pragmatic trade-offs between immediate delivery needs and long-term sustainability, plus the confidence to work through ambiguity, dependencies, risk, and changing priorities without compromising engineering quality. 

What technical skills are required for this role? 

This is an opportunity to bring strong hands-on backend engineering experience and take ownership of enterprise API and integration services. Experience within banking, payments, cards, merchants, or another regulated environment would be beneficial. We are looking for candidates with 7+ years of relevant professional engineering experience, including experience in: 

• Core Development: Strong hands-on experience with Java and Spring Boot/Spring for building enterprise-grade API and integration services. 

• API Design & Gateway: Experience designing and implementing RESTful APIs, including API contracts, specifications, request and response payloads, data mapping, authentication, and error handling, secured via Kong using REST and JWT. End-to-end delivery goes through Kong, so a solid understanding of gateway-based integration is essential. 

• Build & Container Platform: Proficient with Gradle for build management and Docker for containerisation, with services deployed and run on OpenShift and EKS/Kubernetes. 

• CI/CD & Delivery Tooling: Familiarity with the bank's standard pipelines: Bitbucket for source control, Jenkins for build, and Spinnaker for deployment. 

• Secrets Management: Experience using HashiCorp Vault for secure storage and management of API keys, passwords, and other secrets. 

• Messaging & Data: Depending on requirements, experience with IBM MQ using JSON over MQ and/or Kafka for messaging and event-driven integration, and PostgreSQL Aurora for data persistence. 

• Testing: Experience with JUnit, REST Assured, and TestNG for unit and API/integration testing, with end-to-end test coverage validated through Kong. 

• Tooling: Comfortable working in a modern Java IDE. 

• Domain Knowledge: An understanding of cards and card or merchant data flows would be beneficial. 

What attributes will this person display in order to be successful in this role? 

• Hands-on Technical Leadership: You lead through delivery, sound engineering judgement, and practical guidance, while remaining actively involved in design, coding, testing, and production support. 

• End-to-End Ownership: You take responsibility for complex features and services from problem definition and design through deployment, support, and ongoing improvement. 

• Problem-Solving Under Ambiguity: You shape unclear problems, make pragmatic trade-offs, and guide others toward solutions that balance technical and business constraints. 

• Quality and Risk Mindset: You build reliability, security, performance, and testability into solutions and raise technical or operational risks early. 

• Coaching and Knowledge Sharing: You grow others through mentoring, pairing, code and design reviews, constructive feedback, and clear technical documentation. 

• Collaboration and Communication: You communicate clearly with technical and non-technical stakeholders, build trusted relationships, and contribute constructively to cross-team decisions. 

• Continuous Improvement: You seek feedback, stay curious, and use evidence, operational learning, and AI tools to improve engineering practices, team processes, and services. 

Nau Mai ki te Pēke o Aotearoa | Come to the Bank of New Zealand

Please note applications close Friday 16 October 2026.

This is an exciting opportunity to join us!  We're bold thinkers who are taking brave steps to create a company that people want to work for, and customers want to bank with. If you're ready to join a fun organisation where we are proud of our culture and how we are helping New Zealander's to 'Find their way', then show your interest by submitting your application - we can't wait to read it. 

Ehara taku toa i te toa takitahi, engari he toa takitini" - Success is not the work of an individual, but the work of many.”

Closing Date: 16 October 2026

Applications will be reviewed regularly across the advertising period, but we do reserve the right to close applications early.