Senior AI Software Engineer – AI Centre of Excellence

Fast-growing Global Fintech | London HQ (hybrid) Salary: £80-100k Location: London – 3 days p/w Our client is a leading global payments platform, processing billions of transactions a year for some of the world's best-known digital brands. With a footprint spanning six continents and a reputation for moving fast and thinking big, they're now investing heavily in Generative AI to transform how the business operates — and they're looking for a Senior AI Engineer to help lead that charge. This is a rare opportunity to join a newly established AI Centre of Excellence, working at the cutting edge of applied Generative AI within a high-scale, high-stakes fintech environment. You'll not only build and deploy AI solutions but help shape company-wide AI strategy and best practice. The Role As a Senior AI Engineer, you'll design, build, and deploy AI-driven solutions that enhance products and streamline operations, working closely with product, data science, and engineering teams. You'll also play a key role in mentoring peers and setting the technical direction for AI adoption across the business. Key responsibilities include: * Partnering with cross-functional teams to identify and deliver high-impact Generative AI use cases * Designing and building APIs and microservices that embed AI capabilities into core workflows * Developing, fine-tuning, and deploying LLM-based applications (chatbots, assistants, knowledge extraction tools, etc.) * Architecting scalable AI infrastructure on AWS, GCP, or Azure using containerisation and Infrastructure-as-Code * Implementing CI/CD pipelines and secure, compliant AI deployment practices * Building intuitive interfaces for teams to interact with AI-driven features * Continuously optimising the performance, reliability, and scalability of AI systems What You'll Bring * Hands-on experience with LLMs (GPT, BERT, Llama, Gemini, etc.) applied to real-world problems * Strong backend engineering skills, including RESTful APIs and microservices architecture * Proficiency in Python and/or JavaScript, with familiarity in AI frameworks such as LangChain or PydanticAI * Solid grounding in cloud computing (AWS, GCP, or Azure), Docker, Kubernetes, and Terraform * Strong problem-solving ability and comfort operating in a fast-paced environment * Excellent communication and cross-team collaboration skills Nice to Have * C# or Java proficiency * Frontend experience with JavaScript/TypeScript and React * Experience fine-tuning and prototyping Generative AI applications * Awareness of ethical AI practices and AI governance standards * A track record of rapid prototyping with measurable business impact * Experience with distributed systems and large-scale data processing * Open-source contributions or a strong GitHub portfolio * Prior experience in the payments industry (a strong plus)