Senior Full-Stack Engineer - AI Agent Platform in London

We are building an AI-powered financial crime investigation platform that is transforming how Ebury's compliance teams work. Our AI agents will process thousands of screening cases, reducing analyst workload while maintaining regulatory standards. We are looking for a Senior Full‑Stack Engineer to help us scale our platform and raise the engineering bar. You will architect and deliver complex features across the entire stack—from React frontends to Python backends to LLM integrations—while mentoring teammates and shaping our technical direction. This is a unique opportunity to work at the intersection of AI/ML, fintech, and compliance—building production AI systems that handle real financial crime investigations at scale.

What You’ll Do

• Architect and build end‑to‑end features across our React frontend and FastAPI backend, making sound technical decisions that balance speed with maintainability.
• Design AI agent workflows using LangGraph for screening automation, RAG pipelines, and multi‑agent orchestration.
• Lead technical initiatives—own complex features from design to production, breaking down ambiguous problems into actionable work.
• Integrate complex data sources (internal APIs, third‑party services like LexisNexis, data warehouse) with robust error handling and observability.
• Improve platform reliability—implement monitoring, alerting, and performance optimizations for production AI systems.
• Mentor and uplift junior and mid‑level engineers through code reviews, pairing, and technical guidance.
• Shape engineering practices—contribute to architecture decisions, coding standards, and team processes.
• Collaborate cross‑functionally with Product, Design, Compliance, and other engineering teams to deliver impactful solutions.

Tech Stack

• Frontend: React, TypeScript, Material‑UI, Module Federation (Micro‑frontend architecture), Vite, Vitest
• Backend: Python 3.13, FastAPI, LangGraph (AI agent orchestration), LlamaIndex (RAG/vector search), AWS Bedrock, DynamoDB, OpenSearch
• Infrastructure: AWS (ECS Fargate, Lambda, API Gateway, S3), Terraform, GitHub Actions, Docker, Kubernetes, Sentry, Langfuse (LLM observability)

Product & Leadership Focus

• Greenfield AI Product: You will help shape a product from early stages, not maintain legacy code. Your architectural decisions will have lasting impact.
• Technical Leadership: Drive technical direction for a growing team. Mentor engineers and establish patterns that scale.
• Cutting‑Edge AI: Work with the latest LLM technologies in production—LangGraph, RAG, multi‑agent systems, and more.
• Real Impact: Our AI agents process thousands of compliance cases. You will see your work making a difference within weeks.
• Startup‑within‑Enterprise: Small, autonomous team with startup speed, backed by enterprise resources and stability.

Must Have

• 5+ years of professional software engineering experience.
• Strong React + TypeScript skills—architect complex frontend applications with good state management, performance, and testing.
• Strong Python backend experience—FastAPI, Django, or Flask with async programming, clean architecture, and production‑grade code.
• System design skills—design scalable, maintainable systems and articulate trade‑offs clearly.
• API design expertise—REST, WebSockets/SSE, and understanding of distributed systems patterns.
• Database proficiency—SQL and NoSQL (DynamoDB, PostgreSQL, OpenSearch), including query optimization and data modeling.
• Testing mindset—write comprehensive tests and advocate for quality across the team.
• Ownership mentality—take features from idea to production, proactively identifying and solving problems.
• Strong communication—explain complex technical concepts to engineers and non‑engineers, and write clear documentation.
• Mentorship ability—enjoy helping others grow and have experience guiding less experienced engineers.

Nice to Have

• LLM/AI experience—LangChain, LangGraph, RAG pipelines, prompt engineering, or fine‑tuning.
• Production AI systems—experience with LLM observability (Langfuse), token management, streaming, and reliability patterns.
• AWS expertise—Lambda, ECS, DynamoDB, OpenSearch, Bedrock, or similar cloud services.
• Streaming architectures—SSE, WebSockets, event‑driven systems.
• Fintech/compliance background—AML, sanctions screening, KYC, or regulated industry experience.
• Micro‑frontend experience—Module Federation, independent deployability.
• Infrastructure as Code—Terraform, CDK, or similar.

What Sets a Senior Apart

• Technical leadership—identify the right problems to solve and influence technical direction.
• Systems thinking—consider the broader context: scalability, security, observability, and maintainability.
• Proactive communication—surface risks early, propose solutions, and keep stakeholders informed.
• Quality advocacy—raise the bar for testing, code review, documentation across the team.
• Pragmatic decision‑making—balance ideal solutions with delivery timelines, making conscious trade‑offs.
• Continuous learning—stay current with industry trends and bring new ideas to the team.

About Ebury

Ebury is a global fintech firm dedicated to empowering businesses to expand internationally through tailored and forward‑thinking financial solutions. Since its founding in 2009, Ebury has grown to a diverse team of over 1,700 professionals across 40+ offices and 29+ markets worldwide. Joining Ebury means becoming part of a collaborative and innovative environment where your contributions are valued. You will play a key role in shaping the future of cross‑border finance, while advancing your own career in a dynamic, high‑growth industry. Ebury is a FinTech success story, positioned among the fastest‑growing international companies in its sector. Founded in 2009, Ebury is headquartered in London and has more than 1,700 staff with a presence in more than 29 markets worldwide. Cultural diversity is part of what makes Ebury a special place to be. From Sao Paulo to Dubai, Vancouver to Auckland, we enjoy sharing team experiences and celebrating success across the Ebury family. Hard work pays off: in 2019, Ebury received a £350 million investment from Banco Santander and has won internationally recognised awards including the Financial Times “1000 Europe’s Fastest‑Growing Companies.” Our proudest achievement is our great people—enthusiastic, innovative, and collaborative teams, always ready to disrupt and revolutionise the fast‑paced FinTech sector. At Ebury, we are committed to building a workplace where everyone feels valued, supported, and empowered to thrive. We are proud to have active employee networks and ESG initiatives that reflect our inclusive culture, including our Women’s Network, LGBTQIA+ Network, and Veterans Network. We believe in inclusion, stand against discrimination in all forms, and have no tolerance for intolerance of differences that makes us a modern and successful organisation. At Ebury, you can be whoever you want to be and still feel a sense of belonging no matter your story because we want you and your uniqueness to help write our future.

Please submit your application on the careers website directly, uploading your CV/resume in English.