Full Stack Engineer - AI Systems

Location: UK Remote/Hybrid Job Type: Permanent, Full-Time Salary: £120,000 + Equity

A high-growth AI startup is seeking a Full Stack Engineer - AI Systems to help build the next generation of AI-native productivity products.

This is an opportunity to join a small, highly talented engineering team building intelligent systems that go far beyond traditional chat applications. The company is developing a proactive AI assistant capable of managing workflows, maintaining context, interacting with tools, and completing real-world tasks with minimal user input.

You'll work at the intersection of product engineering, AI systems, and user experience, helping to transform advanced AI capabilities into reliable, production-grade solutions used by people every day.

As a Full Stack Engineer - AI Systems, you will play a key role in designing, building, and scaling AI-native workflows across Front End, Back End, and AI infrastructure.

You will be responsible for creating systems that can reason, plan, execute tasks, recover from failures, and provide a seamless user experience.

This role is ideal for engineers who enjoy solving complex technical challenges and want to work on cutting-edge AI products.

• Build end-to-end features across Front End, Back End, and AI systems.
• Develop scalable applications that support intelligent workflows.
• Deliver production-ready solutions focused on user impact.

• Design and implement agent workflows capable of multi-step reasoning and task execution.
• Build systems that coordinate planning, tool usage, recovery, and completion across complex workflows.
• Integrate LLMs, retrieval systems, memory layers, and external services into user-facing products.

• Design low-latency, Real Time AI experiences.
• Implement monitoring, observability, and evaluation frameworks.
• Improve workflow reliability and build robust fallback mechanisms.
• Optimise performance across AI-powered applications.

• Work closely with Product, Engineering, and Machine Learning teams.
• Contribute to architectural decisions and product strategy.
• Continuously improve features based on user feedback and production insights.

• Strong commercial experience as a Full Stack Engineer.
• Experience developing both Front End and Back End applications.
• Solid understanding of system design and API architecture.
• Experience building AI-powered products using:
  • Large Language Models (LLMs)
  • Retrieval-Augmented Generation (RAG)
  • Agentic systems
  • AI workflows
• Proven track record of delivering features from concept through to production.
• Strong problem-solving and decision-making skills.
• Comfortable working in a fast-paced startup environment.

• Building autonomous or agent-based systems.
• Working with model evaluation and testing frameworks.
• Experience with vector databases and retrieval technologies.
• Kubernetes and cloud-native infrastructure.
• Real Time application optimisation and observability tooling.

• Next.js
• Python
• Node.js
• PyTorch
• OpenAI & Anthropic APIs
• Open-source LLMs
• SQL & NoSQL Databases
• Docker
• Kubernetes

• Competitive salary and equity package.
• Opportunity to work on cutting-edge AI technology.
• Significant ownership and autonomy.
• Direct influence over product direction and technical architecture.
• Fast-moving, highly collaborative environment.
• Exposure to some of the most challenging problems in AI, including:
  • Agent orchestration
  • Workflow automation
  • Persistent memory
  • Reasoning systems
  • Reliability engineering

You thrive in environments where ambiguity is common, ownership is expected, and innovation happens quickly.

You're excited by the idea of building products that could fundamentally change how people interact with software and leverage AI in their daily lives.

If you're passionate about AI, product development, and building intelligent systems at scale, we'd love to hear from you.

Apply now for a confidential discussion.