Principal Full Stack Engineer - TypeScript, React, Node, Agentic Workflow (Claude Code) - OUTSIDE at Smart-Sourcer, Remote, 6 Months, £875-£900 per day

Principal Full Stack Engineer - TypeScript, React, Node, Agentic Workflow (Claude Code), AWS, Forward Deployed, AI-Native Engineering - OUTSIDE IR35

Reporting to the Director of Engineering, this is a genuinely outstanding contract opportunity for a rockstar Principal Engineer to lead the development of a greenfield SaaS product. We're looking for a best of breed', deeply senior, technically hands-on engineer who thrives in complex problem spaces and fast-moving start-up & scale-up environments. You'll need a genuinely Product Centric mindset and approach twinned with experience of AI-Native Engineering and Agentic Workflow.

You'll be Embedded into a product squad, frequently working Forward Deployed; sitting shoulder-to-shoulder with clients to understand their workflows, shape solutions in Real Time, and ship production-grade software that transforms how they operate.

You'll own outcomes end-to-end across the stack, setting the technical bar for the squad and helping define the future of AI-native engineering.

Skills we're looking for:

• Senior-to-Staff-level Full Stack Engineer with deep, current expertise in TypeScript, React and Node; comfortable reasoning across the entire stack from database design to DOM performance.
• Authority in React and the modern Front End ecosystems; component-driven architecture, design systems, advanced state management (Redux Toolkit, Zustand, TanStack Query or Apollo), and modern toolchains (Vite, ESBuild) with pnpm/yarn/npm.
• Strong Node.js engineering capability; REST and GraphQL API design, integration patterns, relational/NoSQL modelling, and practical experience deploying into modern cloud/serverless environments (AWS and Cloudflare preferred).
• Proven experience with Claude Code and advanced agentic workflows; shipping real work using multi-agent patterns, orchestrating sub-agents, managing context, defining custom commands/skills and scaling AI-assisted delivery across a team.
• Exceptional communication and client readiness; you've worked Forward Deployed or in comparable client-facing roles, can run discovery sessions, challenge requirements constructively, and turn whiteboard conversations into shippable code.
• A strong product mindset; comfortable operating without a traditional Product Owner, making sensible trade-offs, prioritising ruthlessly and owning outcomes.
• A keen eye for design; able to interpret a design system and produce intuitive, interactive UX without needing high-fidelity mock-ups.
• Rigorous engineering standards; Git-based workflows, trunk-based development, CI/CD (GitHub Actions), comprehensive testing (Jest, React Testing Library, Playwright), accessibility, performance and secure-by-default coding.
• Technical leadership without the title; lifting teams through pairing, mentoring, PR review and example.
• Outcome-oriented pragmatism; comfortable with ambiguity, biased to shipping, and able to make sensible calls on scope, sequencing and technical debt under pressure.

What You'll Do:

• Architect, build and ship complex Full Stack TypeScript applications; owning substantive feature sets end-to-end across React front-ends and BFF Node services.
• Operate as a Forward Deployed Engineer; working directly with clients to elicit requirements, shape solutions, prototype live in the room and translate messy real-world workflows into elegant, production-ready software.
• Own each feature's solution end-to-end; partnering with Business Analysts on high-level problem framing, then driving product thinking, scoping, trade-offs and delivery yourself.
• Leverage Claude Code and advanced agentic workflows at pace; orchestrating sub-agents, managing context, running parallel workstreams and embedding AI-native patterns into everyday engineering.
• Craft beautiful, highly interactive UX workflows from low-fidelity inputs; interpreting our design system and producing polished UI without waiting for polished Figma.
• Shape architecture and technical direction; making well-reasoned decisions on frameworks, patterns, state management, API design and performance.
• Champion engineering excellence; test coverage, peer review, CI/CD discipline (GitHub Actions), secure coding, accessibility (WCAG) and performance.
• Mentor and elevate engineers around you through pairing, PR review, architectural guidance and practical coaching on AI-assisted development.

£875-£900 per day OUTSIDE IR35. 100% remote. 6 months rolling.