Job Title: Senior Applied AI Engineer Salary: Up to £140,000 base Location: London – Moorgate | Hybrid, 2 days per week in the office Work Type: Permanent Role: We’re working with an exciting AI technology business looking for a Senior Applied AI Engineer to join the team building and improving its production LLM systems. This is a hands-on engineering role for someone who wants to work on real-world AI problems where the technology is already being used in production. Rather than focusing on training models or open-ended research, you’ll be solving the challenges that come with making LLM-powered products genuinely work at scale. You’ll have the opportunity to influence how the product evolves, working closely with Product to improve quality, reduce cost and latency, build better evaluation frameworks and solve real production failures. The engineering environment is also heavily AI-native, with tools such as Claude Code forming a key part of how the team builds and ships software. Responsibilities: • Build, improve and maintain production LLM systems • Improve the cost and latency of LLM-powered features without sacrificing accuracy • Design and implement evaluation frameworks that can reliably measure whether changes genuinely improve the product • Investigate production failures raised by analysts, identify root causes and implement effective fixes • Work across areas including RAG, prompting and agentic systems • Partner closely with Product to shape new functionality and take ideas through to production • Use AI-native engineering tools such as Claude Code as part of your day-to-day development workflow • Make sound technical decisions when working through ambiguous engineering problems Required Skills: • 4+ years of experience building production software • Experience shipping LLM-powered systems that have been used by real users • Hands-on experience across areas such as RAG, prompting and/or agents • Strong production engineering fundamentals, including an understanding of reliability and incident response • Good technical understanding of LLMs, including concepts such as sampling parameters and embeddings • Experience designing meaningful evaluations for AI/LLM systems • Comfortable using agentic development tooling such as Claude Code, Codex or similar • Experience working and shipping at pace • Strong communication skills with the ability to explain technical decisions clearly and concisely Why should I apply? This is an opportunity to move beyond LLM prototypes and work on the difficult engineering problems that appear when AI systems are operating in a real production environment. You’ll be able to see the impact of your work directly – whether that’s improving the quality of outputs, making the platform faster and more cost-effective, solving production issues or influencing what gets built next. You’ll also be joining an engineering environment that actively embraces AI-native development rather than simply experimenting with it on the side. If you’re an experienced software engineer who has already shipped LLM systems and you want your next role to combine hands-on engineering, applied AI, product influence and genuine production challenges, this could be a great next step. Interested? Apply for the role today or send your CV to (url removed)