MCS Group are seeking a Lead Software Engineer with deep commercial experience in Python for an exciting new role in a scaling technology company. A perfect opportunity for a senior Python engineer who wants to build real, high-impact AI systems and have true autonomy in an exciting organisation. You'll join a growing team developing next-generation AI solutions for some of the most complex and secure environments in the world across a range of diverse sectors. Our client is an industry leader when it comes to AI. Their mission is to redefine how humans and machines work together; building AI that is safe, reliable and genuinely useful. You'll be at the heart of it: designing, prototyping and delivering LLM-powered applications and agentic workflows that solve real-world client challenges. The Role The Lead Engineer will build and extend platform capabilities using Python, including APIs, integrations and backend services. Implement testing and evaluation frameworks covering prompt quality, agent behaviour, and output reliability. Apply modern AI technologies where appropriate, such as RAG/GraphRAG, knowledge graphs, vector databases and data pipelines. Architect scalable, cost-effective solutions that balance innovation with constraints such as compliance, performance and security. Lead technical discussions and support less experienced engineers. Solve complex problems across a wide variety of client environments. Contribute to a culture of learning, coaching and technical excellence. The Person Experience You'll have strong experience as a software engineer, ideally building production-grade applications and products in Python You'll have an interest in AI and an awareness of LLM APIs, including function calling, prompt engineering and evaluation. Proven backend/API development experience with FastAPI or similar. Comfortable working within agile engineering teams. Salary Up to £85,000 with a leading benefits package which includes amazing annual leave entitlement (one of the best in the private sector) and share options. To speak in absolute confidence about this opportunity, please send an up-to-date CV via the link provided or contact Chris Busby, Associate Director - IT Recruitment, at MCS Group Even if this position is not right for you, we may have others that are. Please visit MCS Group to view a wide selection of our current and exclusive roles All conversations will be treated in the strictest of confidence. Skills: Python Developer AI Engineer Software Engineer Solutions Engineer Software Developer Benefits: Work From Home