Senior Full-Stack Engineer

Senior Full-Stack Engineer

Location: Bristol

Engagement Type: Permanent or Contract

Day Rate / Salary: £350–£500 per day (contract) or permanent package by discussion

Work Model: Hybrid - Bristol office, flexible by agreement

**Please do not apply if you require sponsorship**

About the Role

We’re looking for a Senior Full-Stack Engineer to join the product engineering team at RC Fornax.

This role will initially focus on building a new AI-enabled product, a structured document generation and workflow tool that transforms unstructured inputs into high-quality, structured outputs through analysis, drafting, review, and publishing workflows.

The product sits within a broader defence and procurement platform, where outputs directly support real-world engineering, delivery, and supplier decisions.

The early emphasis is on getting this product built quickly and properly. Over time, this role will expand to work across the wider platform as part of a small, collaborative engineering team.

We’re looking for a pragmatic, delivery-focused engineer who is comfortable working across the stack, but whose strongest value comes from backend systems, AI workflow orchestration, and turning complex product workflows into reliable software.

You’ll own vertical slices of the product, contribute to technical decisions, and help shape how we build and operate the platform as it evolves.

This is applied AI product engineering. The focus is on building reliable systems around structured generation, agent-driven workflows, and multi-step processes, not frontend-heavy work, and not ML research.

You’ll work closely with product and leadership in a small team environment, with real ownership and direct impact.

Technical Environment

You’ll be working within an established monorepo and product architecture, including:

• Frontend: Next.js, React, TypeScript, Tailwind
• Backend / Data: Convex (real-time database, serverless functions)
• AI orchestration: AI SDK + OpenAI (structured generation, agentic workflows)
• Auth: Clerk
• Monorepo: Turborepo with shared packages and strict conventions

What You’ll Do

• Build a new AI-enabled product from the ground up as a core platform capability
• Design and implement backend workflows for AI-assisted document analysis, structured generation, agent-driven interactions, and multi-step processes
• Develop full-stack features across frontend and backend
• Design APIs, data models, and workflow/state logic for complex systems
• Build agentic workflows (e.g. conversational interfaces that guide users through structured output creation)
• Work with document ingestion, extracted inputs, prompts, structured outputs, validation, retries, and error handling
• Translate complex product workflows into clean, maintainable engineering solutions
• Collaborate closely with product to shape scope and iterate quickly
• Contribute to CI/CD, environments, and production readiness as the product matures
• Implement secure and reliable engineering practices suitable for regulated and defence-related environments
• Over time, contribute across the wider product stack

What We’re Looking For

• Strong full-stack engineering experience
• Strong TypeScript experience
• Strong React and Next.js experience
• Strong backend and system design capability
• Experience building APIs and managing application data models
• Experience building or owning complex multi-step workflows (not just CRUD apps)

Core Requirement:

• Production AI workflow experience - building reliable AI-assisted systems, including structured generation, prompt orchestration, agentic patterns, validation, retries, and failure handling
• Strong understanding of how applications behave in production (deployments, environments, observability, reliability)
• Comfortable debugging production issues across environments
• Experience improving or hardening early-stage systems
• Pragmatic problem solver with a strong delivery mindset
• Product-minded engineer who contributes to solution design, not just implementation
• Actively uses modern AI development tooling (e.g. Cursor, Copilot, Claude)
• Right to work in the UK

Nice to Have

• Experience building AI agents or agentic workflows
• Experience working with NoSQL or real-time databases (or willingness to learn quickly)
• Experience with document ingestion or file-heavy systems
• Experience with PDF generation or e-signature integrations
• Experience with CI/CD, logging, monitoring, or alerting
• Experience with messaging or event-driven systems
• Experience working on SaaS or platform products
• Experience in regulated or defence-related environments
• Experience contributing to or delivering 0 to 1 product builds

What Success Looks Like

• Helped take a new AI-enabled product from concept to a working product quickly
• Built reliable AI-assisted workflows for structured generation and user-guided outputs
• Delivered high-quality product features across backend and frontend
• Improved reliability and clarity of AI-driven processes and user feedback
• Contributed effectively to the wider engineering environment and product evolution

What We Offer

• Opportunity to build a core AI-enabled product from the ground up
• Real ownership over product and technical decisions
• Work that directly impacts defence, engineering, and procurement outcomes
• A small, high-trust team working closely across product and engineering
• Flexible engagement (contract or permanent) and hybrid working by agreement
• The chance to shape both a new product and the broader platform over time

Additional Information

Right to work in the UK is required.

Eligibility for UK Security Clearance (SC) is great but not essential.