Founding Software Engineer

Full Stack Engineer - AI Systems Location: UK Remote / Hybrid Job Type: Permanent, Full-Time Salary: £120,000 + Equity About the Opportunity 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. The Role As a Full Stack Engineer - AI Systems, you will play a key role in designing, building, and scaling AI-native workflows across frontend, backend, 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. Key ResponsibilitiesProduct Development

Build end-to-end features across frontend, backend, and AI systems.

Develop scalable applications that support intelligent workflows.

Deliver production-ready solutions focused on user impact.

AI & Agent Systems

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.

Reliability & Performance

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.

Collaboration

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.

Required Skills & Experience

Strong commercial experience as a Full Stack Engineer.

Experience developing both frontend and backend 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.

Desirable Experience

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.

Technology Stack

Next.js

Python

Node.js

PyTorch

OpenAI & Anthropic APIs

Open-source LLMs

SQL & NoSQL Databases

Docker

Kubernetes

What's on Offer?

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

About You 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.