Principal Full Stack Engineer (React/.NET/Agentic AI) - 6 months contract
UK | Fully Remote (UK-based)
Staff/Principal Full Stack Engineer (Contract)
6 months | £900 per day (Outside IR35)
High-growth Product Engineering Team
Build and evolve a core CRM product used across the business
We're supporting a product-led organisation that is rebuilding and modernising key areas of an existing CRM platform.
This role suits an experienced contractor who enjoys working in brownfield environments, partnering closely with the business, and shaping how a product evolves rather than just delivering tickets.
You'll operate as a senior, hands-on engineer within a growing engineering group, working closely with senior leadership to take the product from where it is today to where it needs to be next.
The role
This is a product-focused engineering position, not a pure delivery role:
- Rebuild and enhance existing CRM features within a live production system
- Work end-to-end across Front End and Back End systems
- Partner closely with engineering leadership to understand product direction and priorities
- Turn business problems into pragmatic technical solutions
- Ship iteratively, build, share, improve
- Contribute to technical direction as the team scales
You'll be joining a collaborative engineering group (circa 20 people, growing), with strong access to decision-makers and clear product ownership.
What they're looking for
- Senior/Staff-level Full Stack Engineer with strong product mindset
- Experience working in brownfield systems and modernising existing platforms
- Comfortable operating beyond code, able to engage with the business and explain trade-offs
- Strong communication skills and confidence working with non-technical stakeholders
- Pragmatic approach: focused on outcomes, not perfection first time
Core technical experience:
- React (modern Front End development)
- .NET (Back End/APIs)
- Exposure to Agentic AI/AI-assisted development (eg Claude Code)
- Cloud experience: Azure and/or AWS
Working model & contract details
- 6-month contract (extensions likely)
- £900 per day, Outside IR35
- Fully remote within the UK
- Occasional office attendance may be required