Senior Software Engineer - AI, Next.js - £110k

Senior Software Engineer – AI, Next.js

Fully Remote – Remote UK

Salaries paying £85k-£110k + Equity

Our client is a forward-thinking AI start-up dedicated to building innovative software solutions powered by cutting-edge AI technologies. Their mission is to revolutionise the B2B software landscape by integrating advanced Large Language Models (LLMs) into seamless, user-centric experiences. They are looking for talented Software Engineers to join their dynamic team and be part of the AI-driven transformation in the tech industry.

About the Role

As a Senior Software Engineer, you will be an integral part of their product team, working within a unified codebase that powers their B2B software and custom AI modules. Your role will encompass the entire feature lifecycle, from initial design and data structuring to advanced AI integration, ensuring robust, scalable, and high-performance solutions.

Key Responsibilities:

• Design, build, and maintain web application features using Next.js, TypeScript, React and Node
• Contribute to and optimise their monorepo, which includes both B2B SaaS platforms and AI/LLM modules.
• Integrate and fine-tune commercially available LLMs (e.g., OpenAI, Gemini) through prompt engineering and inference pipeline management.
• Implement multi-step LLM workflows using orchestration frameworks like LangChain.
• Design, optimise, and manage database architecture using MySQL.
• Develop and maintain type-safe RPC endpoints with tRPC and TypeScript for seamless front-end and back-end communication.
• Rapidly onboard to their modern TypeScript stack, ensuring high-velocity feature delivery.

Required experience:

• Proven experience working within complex, unified codebases that combine application logic with AI/LLM components.
• Expertise in modern web development with Next.js, tRPC, TypeScript, and Prisma.
• Strong understanding of database design and optimisation, particularly with MySQL.
• Hands-on experience integrating with AI models like ChatGPT or Gemini, including prompt crafting and API management.
• Familiarity with LangChain or similar orchestration tools for multi-step AI workflows.
• Ability to quickly learn new technologies and deliver production-ready features in a dynamic environment.

Preferred Qualifications:

• Experience deploying and fine-tuning custom AI models.
• Background in developing B2B software platforms with multi-user support.

If you are excited about building impactful software and diving deep into AI technologies, we want to hear from you, please apply now!