Founding AI Research Engineer (up to £140k)

This role is with one of Dex's trusted partner companies. We work closely with their teams to truly understand their culture, goals, and what they're looking for, so we can match you with the right opportunity and give you context about the role before you commit to a process. *If you're interested sign up to Dex to apply.* Dex is an AI recruiter agent that helps you run your job search. Tell Dex your stack, seniority, and what you want to build. We will manage your applications and surface other opportunities that are a fit. The role This company is building a truly proactive AI assistant that already knows your work. Instead of pulling context at query time, it maintains a living model of a person's entire digital workspace – emails, messages, meetings, documents – and acts on their behalf, drafting replies or preparing for meetings before being asked. It's a fundamentally different approach to AI agents, tackling problems of long-term memory and real-time reasoning that no one has fully solved. The team is small, composed of repeat founders with deep technical expertise, and the product is already in private alpha with high-profile users. This is a founding AI Research Engineer role, owning the research direction for these core problems. You'll work end-to-end on retrieval and knowledge-base systems, reasoning models, and models that understand live screen context, taking them from hypothesis to production. This is applied research with direct user impact, not a publication track. There's no research-to-engineering handoff; you'll build and productionise your own work. The work * Design and implement novel approaches for persistent, long-term memory in AI agents. * Build and optimise retrieval and knowledge-base systems across diverse, messy data sources. * Develop reasoning models that understand and act on live screen and application context. * Own the full lifecycle from research hypothesis through experimentation to production-ready, user-facing features. What You Bring * 5+ years solving research-level problems in NLP, LLMs, or adjacent ML, in industry or academia. * A track record of personally owning and delivering a hard technical project end-to-end, or a relevant PhD. * The ability to implement and build upon research papers, not just apply existing libraries. * Experience with both hypothesis formation/testing and building robust, scalable systems. * Strong Python, cloud infrastructure, and database (SQL/NoSQL) skills. * Willingness to work in person 5 days a week in Elephant and Castle, London. Why apply through Dex This is a rare founding-stage role at a company solving genuinely hard, unsolved problems in AI. Dex helps you cut through the noise: get a direct introduction, skip the cold application, and get properly briefed on the full context before you interview. If you're interested, sign up to Dex to apply - https://jobs.meetdex.ai/jobs/2e31a8c1-9fbf-47c3-878a-42e19e99f009 *As part of the recruitment process at Dex, we process your personal data in accordance with our Privacy Notice for Job Applicants. This notice explains how and why your data is collected and used, and how you can contact us if you have any concerns.*