Software Engineer

Role: Software Engineer

Salary: £45,000 - £55,000 per annum

Location: Central Cardiff (close to public transport links)

About the Role

This is a full-time, permanent role in a growing Cardiff-based technology business that builds and runs its own software platform on the Microsoft stack (C# .NET and SQL Server, with BigQuery also in use).

The CEO is heavily focused on AI and on adopting new technology early, and the engineering team already works this way. All production code is currently written using Claude with engineers reviewing, questioning and shaping what it produces.

Because of this, the role places more weight on understanding software design. You will need to understand how the system is structured, which design patterns are used and why, and how each change affects the wider architecture.

You will not be expected to use Claude straight away. For the first few months you will write code yourself so that you learn the codebase, the data structures and the architecture properly before moving to an AI-assisted workflow.

As the business is growing, you will work with people across different departments to understand their requirements and deliver software that meets them.

Key Responsibilities

Back-end development

• Develop and maintain back-end functionality in C# .NET, applying object-oriented programming principles
• Work with data held in SQL Server and BigQuery as part of day-to-day development, with support provided while you learn.

Working with AI-generated code

• Once you are familiar with the codebase, review code produced by Claude and check that it is correct, maintainable and consistent with the existing architecture.
• Question and refine AI-generated output where it does not follow the right design patterns or would cause problems elsewhere in the system.

Working with the business

• Speak directly with colleagues across the business to understand what they need from the software, and translate that into working features.
• Work within an agile development process, including planning, estimation and regular delivery.

Experience Required

• A minimum of two years of professional software development experience.
• Commercial experience of back-end web development using C# .NET.
• A good working knowledge of object-oriented programming and common design patterns.
• Experience working within an agile team.

Skills & Attributes

• You can explain why code is written a certain way, not just what it does.
• You are comfortable reading and critically reviewing code written by someone (or something) else.
• You approach problems analytically and can work through issues methodically.
• You communicate clearly with both technical and non-technical colleagues.
• You are interested in how AI is changing the way software is built and want to work in that environment.

Desirable

• Any exposure to SQL Server or BigQuery (not essential, as this can be learned on the job).
• Any experience using AI coding tools such as Claude, Copilot or Cursor.

What’s on Offer

• Hands-on experience of an engineering workflow where AI writes the code and engineers are responsible for design, review and quality.
• A structured start, with the first few months spent learning the codebase by writing code yourself before moving to AI-assisted development.
• Close contact with the wider business, so you see how your work is used and why it matters.
• A business led by a CEO who actively invests in new technology and expects the engineering team to adopt it.
• A Cardiff office base with hybrid working once you are settled in, moving from 4 days per week in the office for the first 2 months to a minimum of 2 days per week after that.