Senior Full Stack Developer

About Zenzero Zenzero is one of the UK's fastest-growing technology companies. Named a Top 8 Technology Company at the British Business Awards 2026, recognised by Deloitte as a Best Managed Company, and featured in the Sunday Times Hundred (an annual ranking of the UK's fastest-growing private companies) in both 2025 and 2026, we hold Microsoft Solutions Partner status across all six designations, putting us in the top tier of UK Microsoft partners. The accolades reflect something real: a business that is scaling fast, executing well, and building something that lasts. 
 
We're on a mission to make technology genuinely work for mid-market businesses, covering managed IT, cyber security, cloud, and AI solutions that actually move the needle. The demand is growing, and so are we. 
 
We're also a certified B Corp and Scale Up Award winner. That combination matters to us: high growth and high standards aren't in conflict here. Fast growth, high standards, real impact. If that sounds like your kind of place, keep reading. 
 
About the Role 
 
We are recruiting two senior .NET Developers to support growing demand across our Digital Development Services (DDS) team. With a strong client project pipeline and increasing demand for bespoke software solutions, these roles will play a critical part in delivering high-quality outcomes for our clients. 
 
This is a client-facing consulting position where you will work directly with organisations to design, develop and maintain custom applications and integrations. You will collaborate with project managers, technical specialists and clients throughout the delivery lifecycle, translating business requirements into effective technical solutions. 
 
Success in this role means becoming a trusted contributor who can independently deliver high-quality development work, build strong client relationships, and help the DDS team successfully deliver a growing portfolio of projects. 

Essential 

• Strong commercial experience developing solutions with C# and .NET (Core and/or Framework).
• Experience with ASP.NET MVC, Web API or Blazor.
• Knowledge of Microsoft Azure services including App Services, Functions, Logic Apps and Storage.
• Strong SQL Server and relational database design skills.
• Experience developing RESTful APIs and third-party integrations.
• Working knowledge of Git-based collaborative development workflows.
• Experience using Azure DevOps and CI/CD pipelines.
• Ability to work directly with clients, gather requirements and communicate technical concepts clearly.

Desirable 

• Experience with Python, PHP, Java or other back-end technologies.
• Exposure to React, Angular or Vue.
• Experience integrating with Microsoft 365, SharePoint, Dynamics or Business Central.
• Previous experience in an MSP, consultancy or other client-facing development environment.

Responsibilities  

• Design, develop and maintain bespoke applications and system integrations for clients.
• Build full-stack solutions using Microsoft .NET and Azure technologies.
• Contribute to solution architecture and technical design discussions.
• Write clean, well-tested and well-documented code that supports long-term maintainability.
• Partner with project managers, technical teams and clients throughout project delivery.
• Drive successful client outcomes through effective communication and consultancy.
• Own the delivery of development tasks from requirements through to deployment.
• Support and mentor junior team members where appropriate.

Benefits 

• Private health insurance
• Generous holiday allowance + a day off on your birthday
• Flexible working patterns
• Enhanced pension contributions
• Regular social events across all our offices