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.
The role
This company is building the future of AI for regulated industries. They combine large language models with a proprietary symbolic reasoning engine, delivering accurate, explainable, and auditable decisions. Their technology is already live with tier-1 banks and leading accountancy firms, and they're backed by leading investors. Founded by a recognised leader in AI who previously built the technology behind a widely-used voice assistant, they're now scaling from bespoke enterprise engagements to a public API platform.
As a Senior Software Engineer, you'll be hands-on building the core of that platform. This isn't just integrating existing LLMs; it's tackling genuinely novel problems at the intersection of classical symbolic AI and modern LLMs. You'll own systems end-to-end, from ideation to production, working in a small, high-calibre team alongside research engineers and applied scientists. Expect real ownership, not just picking up someone else's spec.
The work
- Design and build public API infrastructure, including authentication, scalability, and developer tooling.
- Develop document-ingestion pipelines to handle diverse formats and regulatory jurisdictions.
- Create and implement evaluation frameworks to measure and continuously improve system accuracy.
- Contribute to the core symbolic reasoning engine: decision-tree evaluation, rule generation, and knowledge-graph construction.
- Solve genuinely novel problems like representing complex regulatory knowledge as machine-evaluable rules.
What You Bring
- Strong hands-on Python, writing well-typed, well-tested code in a collaborative monorepo.
- A track record of taking new systems from ideation to production, owning them end-to-end.
- Experience putting AI into production, specifically with agentic systems, LLM integration, and robust evaluation/iteration.
- Ability to tackle non-trivial algorithms and data structures, valuing problem complexity over specific tools.
- Cloud infrastructure experience (AWS preferred): S3, ECR, ECS/EKS, and infrastructure managed via Terraform or similar.
Senior Software Engineer (up to £130k) employer: Dex
Join a pioneering early-stage venture-backed company at the forefront of building foundation models for extreme physics, where you will have the unique opportunity to shape the engineering culture from day one. With a strong focus on innovation and collaboration, this role offers competitive compensation, a dynamic work environment, and the chance to contribute to critical advancements in global infrastructure and energy. You'll be part of a small, research-heavy team that values your expertise and encourages personal growth, making it an excellent place for those looking to make a meaningful impact.
