Senior .NET Engineer & Team Lead (Onsite)

Advanced Secure Technologies | B Corp™; Cardiff; On-site; GBP 60,000 - 66,000; Full time

Benefits offered by this job

Salary £60k-£66k

Annual bonus up to £5k

Career development

Gym/parking/eyecare

Private online GP

Job summary

Advanced Secure Technologies is seeking a Senior Software Developer and Team Lead to drive delivery of .NET features in our on-site Cardiff team. You will contribute as a senior developer while leading sprint delivery, mentoring peers, and shaping architectural direction.

Based in St Mellons, Cardiff, you’ll work 8.30am–5pm in office five days a week, with a focus on enterprise-grade security solutions and event-driven SaaS microservices. Competitive salary with up to £5k bonus.

Qualifications

• 7+ years' commercial experience delivering modern C# .NET solutions, including at least a year at Senior level.
• Strong commitment to engineering best practices, including writing clean, maintainable and testable code.
• Experience of Clean Architecture or similar modern approaches such as hexagonal or onion architecture.
• Clear communication skills and ability to collaborate across diverse engineering teams.
• Experience mentoring and supporting other developers.

Responsibilities

• Design and deliver new features and platform improvements using .NET and modern technologies as a senior contributor.
• Help shape technical direction, architecture, and engineering standards.
• As Team Lead, own sprint delivery, coordinate priorities, resolve blockers, and support releases.
• Mentor and guide other developers to foster a collaborative, high-performing culture.

Skills

Senior developer

C# .NET

Unit testing

Clean Architecture

Mentoring

UK work eligibility

On-site work

Tools

RabbitMQ

Docker

Kubernetes

Azure DevOps

CI/CD

Azure

SQL

Job description

Advanced Secure Technologies is seeking a Senior Software Developer and Team Lead to drive delivery of .NET features in our on-site Cardiff team. You will contribute as a senior developer while leading sprint delivery, mentoring peers, and shaping architectural direction.

Based in St Mellons, Cardiff, you’ll work 8.30am–5pm in office five days a week, with a focus on enterprise-grade security solutions and event-driven SaaS microservices. Competitive salary with up to £5k bonus.