Fintech Software Tester — Wallet, Card & Api Quality

North Island - Auckland Central Auckland; Auckland; On-site; NZD 120,000 - 150,000; Full time

Job summary

Crossware in Auckland is seeking a Senior Backend Developer to join our team at the office. You will design, build, and maintain scalable C#/.NET backend services and APIs that power real-world applications used by thousands of customers.

You will contribute to architecture, ensure performance and reliability, and collaborate with engineers, product, and support teams. Experience with AKS, Docker, Azure, and CI/CD is highly valued.

Qualifications

• 3+ years of backend development with C# and .NET.
• Strong API design and distributed systems experience.
• Experience with cloud platforms, preferably Azure.
• Experience with SQL and/or NoSQL databases and data modelling.
• Familiar with system design, scalability, and performance.
• Proficient with Git and CI/CD pipelines.
• Knowledge of security, authentication, and best practices.
• Experience modernising legacy systems (e.g., Visual Basic).
• Familiar with AKS and Docker in production.
• Ability to own system stability and production reliability.

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 legacy systems and modernisation efforts
• Collaborate with engineers, product, and support teams to deliver robust solutions
• Contribute to code quality, testing, and deployment practices

Skills

C#

.NET

APIs

Azure

SQL/NoSQL

AKS

Docker

Git

CI/CD

Security

Legacy modernization

Production systems

Tools

AKS

Docker

Git

CI/CD pipelines

Azure DevOps

Job description

Showing 1 Fintech Software Tester Wallet Card Api Quality jobs in Auckland

Crossware is looking for a Senior Backend Developer to join our team in Auckland, working from the Crossware office, 40 hours per week. This is a hands‑on engineering role focused on designing, building, and maintaining scalable backend systems used in real‑world production environments, working on systems that serve thousands of customers, where performance, reliability, and maintainability matter. This is not a greenfield‑only role, you’ll be improving and evolving existing systems while helping shape future architecture.

What You’ll Do:

• 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

What We’re Looking For:

Core Technical Skills

3 Years relevant work experience in the following:

• Strong experience with C# and .NET (Core/Framework)
• Solid understanding of API design and distributed systems
• Experience with cloud platforms (Azure preferred)
• Knowledge of databases (SQL and/or NoSQL) and data modelling
• Familiarity with system design, scalability, and performance optimisation
• Experience with version control (Git) and CI/CD pipelines
• Understanding of security, authentication, and best practices in backend systems
• Experience working with legacy systems and modernisation efforts (e.g. Visual Basic)
• Solid functional understanding of Azure Kubernetes Services (AKS) and Docker containers.
• You understand what it means to run software in production at scale
• You take ownership, not just of features, but of system stability and reliability
• You are comfortable debugging real-world issues across multiple layers
• You are pragmatic and able to work with existing systems, improving them over time
• You care about writing maintainable, well-structured code
• You can use AI tools effectively, while applying judgement, validating outputs, and maintaining engineering standards

Nice to Have

• Experience with Microsoft 365 technologies (Exchange, Graph API, Teams, Outlook)
• Exposure to messaging systems, background processing, or event-driven architectures

How We Work

We don’t expect you to know everything. What matters is your willingness to learn, adapt, and grow beyond your current focus. You’ll be supported by a team that values practical problem‑solving, ownership, and continuous improvement.