Lead Developer - London Stock Exchange Group

We are seeking a highly skilled and hands‑on Lead Java Engineer with AI proficiency to help build the next generation FTSE Russell Index Platform. This platform underpins the calculation and distribution of FTSE Russell's global family of indexes and requires advanced engineering, high‑precision data processing, and deep collaboration across global teams. The role is deeply technical, focused on designing, building, integrating, and operationalising modern software and AI‑driven capabilities across internal platforms and client‑facing products. You will work with innovative technologies, contribute to complex algorithmic design, and drive engineering excellence in a high‑performance, data‑intensive environment.

Key Responsibilities

• Design, develop, and maintain complex Java and Python applications using modern engineering practices; build and embed AI‑powered features into mission‑critical systems.
• Architect and enhance services that support large‑scale, performance‑critical index calculations.
• Collaborate with Product Managers, UX, and engineering teams globally to deliver high‑quality products.
• Lead projects end‑to‑end through requirements, design, development, testing, deployment, and operations.
• Build and maintain automated test suites to ensure performance, scalability, and security.
• Diagnose production issues, identify root causes, and deliver Level 3 support and fixes.
• Conduct peer reviews, provide technical leadership, and mentor junior engineers.

Required Experience & Skills

• 12+ years of hands‑on backend software engineering experience.
• Support the organisation's AI adoption journey; develop and enhance intelligent solutions using LLMs, LangChain, LangGraph, and agentic AI frameworks.
• Establish engineering best practices for safe, scalable, traceable, and production‑ready AI deployments across internal platforms and external product suites.
• Strong knowledge of algorithms, data structures, problem‑solving, and the ability to translate business problems into scalable solutions.
• Good command of coding standards and strong understanding of both high‑level and low‑level software design.
• Expertise in Core Java and Python.
• Experience building highly distributed, data‑intensive systems.
• Proficient with microservices and REST APIs.
• Knowledge of relational databases such as Oracle, SQL Server, and Postgres.
• Familiarity with CI/CD tools (Jenkins, GitLab) and DevOps automation.
• Experience with Docker and Kubernetes.
• Ability to profile JVM applications and optimise performance.
• Prior exposure to Level 3 production support.

Preferred / Nice‑to‑Have Skills

• Experience leading or mentoring a team of engineers.
• Experience within financial services or with financial market data.
• Knowledge of in‑memory caching, Spring Boot, Redis, and Kafka.
• Experience with BDD frameworks such as Cucumber, JBehave, or Karate.
• Experience running Agile teams.

What We're Looking For

A proactive, creative engineering leader who enjoys solving complex problems, working hands‑on with modern technologies, and driving AI‑enabled innovation. If you are passionate about building resilient, intelligent, data‑intensive systems that power global financial markets, we would love to hear from you.

Benefits

LSEG enhances each employee's potential through personal development and a wide range of learning tools, both formal and informal. We offer healthcare, retirement planning, paid volunteering days, and wellbeing initiatives. We are proud to be an equal opportunities employer and do not discriminate on the basis of any protected characteristic. We can accommodate religious practices, disability needs, and other requirements in accordance with applicable law.