Advanced Secure Technologies
Senior Software Developer and Team Lead (.NET)

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Senior Developer and Team Lead (.NET)
Location: St Mellons, Cardiff (Office-based, 5 days a week)
Starting Salary: £60,000 - £66,000 DOE + up to £5,000 annual bonus
Are you an accomplished senior software developer with a proven track record in .NET? Join us at an exciting time in our journey, where you’ll help shape the future of our products as we modernise our enterprise applications with the latest.NET technologies and event-driven SaaS microservice architecture to deliver enterprise-scale solutions.
At Advanced Secure Technologies, we’re a fast-growing, innovative company on a mission to protect organisations from document fraud through cutting-edge security solutions. Based on-site in St Mellons, Cardiff, we’re expanding and need another skilled senior developer to help us scale.
What you’ll do:
- Play a key role in the design and delivery of new features and platform improvements using.NET 10 and other modern technologies, contributing as a senior individual contributor within one of our collaborative engineering teams.
- Share ideas, solve complex technical problems, and help shape the future technical direction, architecture and engineering standards of our products.
- As a Team Lead, take ownership of team sprint delivery, facilitating sprint activities, coordinating priorities, resolving blockers, and helping ensure releases and wider project deliverables remain on track and delivered successfully.
- Support and mentor other developers through technical guidance, collaboration, code reviews, and sharing best practice, while also supporting their career development and contributing to a collaborative, high-performing engineering culture.
What you bring:
- Proven experience operating successfully at senior developer/engineer level within commercial software teams, making strong hands-on technical contributions as a senior individual contributor.
- 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, with experience applying unit and integration testing standards within modern development teams.
- Experience of Clean Architecture or similar modern approaches, such as hexagonal or onion architecture, beyond traditional N-tier designs.
- Strong problem-solving skills, attention to detail, excellent organisation, and clear communication skills, with the ability to collaborate effectively across diverse engineering teams and the wider business.
- Experience mentoring, guiding, and supporting other developers, helping them grow through collaboration, technical guidance, and knowledge sharing.
Reasons to use Rodeo
I’m in my final year doing Economics and I don’t know whether to apply for grad schemes now or do a masters first. What do you think?
Honest answer — it depends on where you want to end up. A lot of top grad schemes (Big 4, civil service, banking) don’t need a masters. Let’s look at the ones you’d be competitive for now, and we can decide if a masters actually adds anything.
Also worth knowing: most autumn 2026 applications are open now. Timing matters more than you think.
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Why you're a good match
StrongYour economics background and your summer at a regional bank line up with what PwC looks for on the consulting scheme. Applications close in four weeks.
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Why you're a good match
You’ve got the grades and the economics background, and your bank internship is exactly the experience this scheme looks for. Apply soon — deadlines close within the month.
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Your summer at the bank plus your econometrics coursework map directly to the day-one responsibilities on this scheme — client modelling, market briefings, and deal support.
Only hits
No noise. No "maybe this fits." Just roles with a clear explanation of why they're right — and where to focus when applying.
Bonus points for:
- Working with enterprise-scale software, microservices, event-driven architecture, or SaaS product development.
- Experience with TDD, DDD, secure coding/OWASP practices, Azure DevOps, CI/CD pipelines, and cloud platforms like Azure.
- Experience with some of the tech we use:.NET Blazor, EF Core, SQL, Redis, Elasticsearch, RabbitMQ, Docker, Kubernetes, or Blockchain.
- Experience using AI tools to improve developer effectiveness, team productivity, and the quality or speed of software delivery.
What we offer:
- Competitive starting salary £60,000 - £66,000 (DOE) + annual bonus potential of up to £5,000.
- A clear career pathway through our grades and beyond with mentoring and skill development support.
- 25 days holiday + Bank Holidays.
- Training and development time, plus training budgets for courses/exams.
- Free gym, secure parking, free eyecare, and a fully stocked kitchen.
- Access to PerkBox for significant retailer discounts.
- Free Private online GP.
- Employee Assistance Programme including specialist clinical support.
- Cycle-to-work schemes.
- A fun, supportive culture in an expanding company.


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Interviews
Our interview process:
- Introductory call: A chance for us to get to know you, and for you to get to know us. We’ll cover your experience, a few competency-based questions, and some light technical discussion.
- Technical interview: Technical questions and discussion around your approach and problem-solving, includes a practical coding exercise focused on real-world problem solving.
- Final conversation: Meet our Managing Director for an informal chat about the role, the team, your potential impact, and the growth opportunity available to you.
Location and hours:
- Onsite, Eastern Business Park, St Mellons, Cardiff, Wales.
- Min Hours: 37.5hrs per week, 8.30am to 5pm Monday to Friday, with up to one hour for lunch.
If you’re looking for a senior engineering role where you can influence technical direction, contribute to modernisation work, and help shape enterprise-scale products, apply now – we can’t wait to see what you’ll bring!
On Site Working:
We’re an office-based team because our culture thrives on collaboration and hands-on support, especially as we grow quickly and onboard new team members. While we don’t offer fully remote or fixed hybrid work, we’re flexible when life happens – ad hoc home working is always an option.
Diversity & Inclusion:
Advanced Secure Technologies is an equal opportunity employer, proud of our ongoing efforts to foster diversity and inclusion. We welcome applicants from all backgrounds and process your personal data in accordance with our Privacy Notice.
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