Senior Backend Engineer - FinTech APIs & Wallet

Foodstuffs; Auckland; On-site; NZD 120,000 - 160,000; Full time

Job summary

Crossware in Auckland is seeking a Senior Backend Developer to design, build, and maintain scalable backend systems used in real-world production environments, serving thousands of customers with focus on performance, reliability and maintainability.

You will evolve existing architectures and contribute to future design choices, collaborating with product and support teams to deliver robust, well-structured solutions in a hands-on engineering role.

Qualifications

• 3 years of relevant back-end experience in C#/.NET and API design.
• Azure cloud experience preferred.
• Knowledge of SQL and NoSQL databases and data modelling.
• Familiarity with system design, scalability, and performance optimisation.
• Experience with Git and CI/CD pipelines.
• Understanding of security, authentication, and backend best practices.
• Experience with legacy systems and modernisation (e.g., Visual Basic).
• Proficiency with AKS and Docker containers.

Responsibilities

• Design, build, and maintain backend services using C# and .NET.
• Develop and maintain APIs (RESTful and/or event-driven).
• Contribute to system architecture and technical design decisions.
• Ensure high performance, scalability, and reliability of production systems.
• Debug and resolve complex issues across backend, frontend, and cloud environments.
• Work with and incrementally improve legacy systems.
• Collaborate with engineers, product, and support teams to deliver robust solutions.
• Contribute to code quality, testing, and deployment practices.

Skills

C# & .NET

API design

Distributed systems

Azure

SQL & NoSQL databases

CI/CD pipelines

Git

Security & authentication

Legacy modernization

AKS & Docker

Tools

Azure

AKS

Docker

Git

Job description

Crossware in Auckland is seeking a Senior Backend Developer to design, build, and maintain scalable backend systems used in real-world production environments, serving thousands of customers with focus on performance, reliability and maintainability.

You will evolve existing architectures and contribute to future design choices, collaborating with product and support teams to deliver robust, well-structured solutions in a hands-on engineering role.