Senior Software Engineer - API

About the role

Westpac NZ is looking for a Senior Software Engineer to design, build and evolve Java‑based API services that power real‑time payment experiences. You will work within the Payments Engineering squad, collaborating with product, platform and engineering teams to shape the API‑first strategy across the bank’s digital ecosystem.

Key responsibilities

• Design, develop and maintain high‑quality Java backend services using Spring Boot or similar frameworks.
• Build and evolve RESTful APIs and micro‑service architectures that support critical payment flows.
• Collaborate with architecture and wider Payments teams to implement architectural changes while delivering new customer features.
• Drive quality engineering practices, including testing, monitoring, performance optimisation and CI/CD pipelines.
• Mentor junior engineers and contribute to a supportive, inclusive team environment.
• Ensure all solutions meet regulatory, security and compliance requirements.

Required profile

• 7+ years of software engineering experience with a strong focus on Java backend development.
• Proven ability to work in complex, parallel‑delivery environments.
• Hands‑on experience building REST APIs, micro‑services and integration solutions.
• Strong collaboration skills across cross‑functional teams.

Required skills

• Java
• Spring Boot (or equivalent)
• REST API design
• Micro‑services architecture
• API platforms and integration patterns
• System design and architecture principles
• Testing, debugging and quality engineering
• CI/CD and DevOps practices