Senior Backend Engineer - C#/.NET, Scalable Systems

Crossware Limited; Auckland; On-site; NZD 120,000 - 180,000; Full time

Job summary

Crossware Limited in Auckland is seeking a Senior Backend Developer to design, build, and maintain scalable backend systems used in real-world production environments. You will work on systems serving thousands of customers, improving performance, reliability, and maintainability while evolving architecture.

You will join a hands-on engineering team, collaborating across product and support to deliver robust, well-structured solutions.

Qualifications

• 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 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

Git

CI/CD

Docker

AKS

Security

VB legacy

AI tools

Tools

Docker

Git

CI/CD

AKS

Job description

Crossware Limited in Auckland is seeking a Senior Backend Developer to design, build, and maintain scalable backend systems used in real-world production environments. You will work on systems serving thousands of customers, improving performance, reliability, and maintainability while evolving architecture.

You will join a hands-on engineering team, collaborating across product and support to deliver robust, well-structured solutions.