Senior Software Engineer

Accelero; Cardiff; Hybrid; GBP 70,000 - 90,000; Full time

Benefits offered by this job

Private healthcare

Enhanced pension

28 days holiday + bank holidays

Hybrid work model

Job summary

Accelero in Cardiff is seeking an experienced Senior Software Engineer to lead technical direction while writing high-quality code. You’ll mentor engineers, review code, and shape how we build and deliver software in a hybrid Cardiff-based role.

You will own backend design, tackle complex SQL tasks, and drive Azure cloud decisions while collaborating with product stakeholders to translate requirements into robust solutions. A clear path to principal roles awaits.

Qualifications

• Proven senior-level C# / .NET Core experience across complex production systems.
• Deep SQL expertise including design, optimisation and performance.
• Solid cloud platform experience, ideally Azure.

Responsibilities

• Designing and building robust backend services and APIs with C# / .NET Core.
• Owning complex SQL work including schema design, performance tuning and data modelling.
• Driving cloud infrastructure decisions and best practices, primarily on Azure.
• Leading code reviews and championing engineering standards across the team.
• Mentoring and supporting junior and mid-level engineers in their development.
• Taking the lead on technical design and architecture discussions.
• Collaborating with product and stakeholders to translate requirements into solid technical solutions.

Skills

C# / .NET Core

SQL

Cloud experience

Tools

Docker

Kubernetes

CI/CD pipelines

Job description

Senior Software Engineer | Cardiff / Hybrid (2 Days Onsite)

We're looking for an experienced Senior Software Engineer to join our client's team in Cardiff. You'll be a technical leader within our engineering squad - setting the standard for code quality, mentoring engineers, and playing a key role in shaping how we build and deliver software.

The Role

This is a hands-on senior role. You'll be writing code every day, but also taking ownership of technical direction, leading by example, and helping to level up the engineers around you.

Day to day you'll be:

• Designing and building robust backend services and APIs with C# / .NET Core
• Owning complex SQL work including schema design, performance tuning and data modelling
• Driving cloud infrastructure decisions and best practices, primarily on Azure
• Leading code reviews and championing engineering standards across the team
• Mentoring and supporting junior and mid-level engineers in their development
• Taking the lead on technical design and architecture discussions
• Collaborating with product and stakeholders to translate requirements into solid technical solutions
• Identifying and resolving technical debt, and advocating for long-term maintainability

Must-have:

• SQL
• Cloud experience - Azure preferred, AWS or GCP also considered

Nice to have:

• CI/CD pipelines, Docker, or Kubernetes
• Microservices or event-driven architecture experience

What We're Looking For

• Proven senior-level C# / .NET Core experience across complex, production systems
• Deep SQL expertise - optimisation, schema design, query performance at scale
• Solid cloud platform experience, ideally Azure
• Demonstrable experience leading technical work and influencing engineering decisions
• A track record of mentoring engineers and raising team capability
• Excellent communication skills - comfortable talking to both technical and non-technical stakeholders
• A collaborative, inclusive leadership style

What's On Offer

• Hybrid working - 2 days in our Cardiff office, rest remote
• 28 days holiday + bank holidays
• Private healthcare & enhanced pension
• Real influence over technical direction and ways of working
• Clear pathway to Principal or Lead Engineer level