Tejas Sharma Leaves Citadel for OpenAI London

Tejas Sharma has joined OpenAI as a member of technical staff and will lead the company’s engineering team in London while working on agentic infrastructure.

Sharma was head of data risk engineering at Citadel’s London office. He joined Citadel in 2021 and led the firm’s London risk data engineering function for just under three years. At OpenAI he will focus on building infrastructure that allows models to take autonomous actions, plan and interact with external services.

Before Citadel, Sharma held senior engineering roles at major technology and data firms. He spent five years at Meta working on Instagram’s machine learning systems and six years at FactSet managing core infrastructure services. His experience covers production machine learning, data systems and platform engineering.

Sharma is one of several senior engineers moving from quantitative trading and hedge funds into AI research and infrastructure roles. Former colleagues from Citadel have taken positions at major AI and technology organisations. Some hires joined while on notice periods or faced contractual limits such as non-compete restrictions; access to roles varies with those constraints.

OpenAI’s London presence has expanded quickly. Official filings recorded about 55 UK employees at the end of 2024, while professional networking data indicates the local headcount has grown to more than 200 people, including over 40 technical staff. The company is advertising multiple engineering and research roles in London as it scales local teams and builds production systems.