Founding AI Systems Engineer Lead

Dex; Greater London; On-site; GBP 90,000 - 150,000; Full time

Job summary

Dex is partnering with a stealth legal AI startup to hire the first full-time engineer who will own the product from day one. You will select the stack, design data infrastructure, and build the agentic layer that detects and triages legal needs before a client asks.

Collaborating with an in-house legal team, you’ll streamline bottlenecks, set technical standards, and hire the next two engineers, shaping the early engineering culture and delivering a production-grade MVP.

Qualifications

• Staff-level engineering experience taking an ambiguous product from 0 to 1 in production at a VC-backed startup.
• Demonstrated track record of shipping production AI-native or agentic systems, with integrations into workspace tools like Slack, Notion, email, or CRMs.
• Pragmatic architectural judgment: ability to scope a clean MVP, make foundational technical choices, and ship fast without over-engineering.
• Experience leading technical direction and mentoring or hiring engineers, while staying hands-on in the codebase.

Responsibilities

• Architect and build the core product from scratch, selecting the initial stack, data infrastructure, and agent frameworks with complete technical ownership.
• Develop agentic systems that plug into company communication channels and workspaces to proactively detect, parse, and triage legal needs.
• Collaborate daily with the in-house legal team to identify manual bottlenecks in early client pilots and convert them into automated, human-in-the-loop workflows.
• Recruit, interview, and onboard the next two founding engineers, establishing technical standards and the early engineering culture.

Skills

Staff-level engineering

AI-native / agentic systems

Architectural judgment

Mentoring or hiring engineers

Tools

Slack

Notion

CRM tools

Email systems

Job description

Dex is partnering with a stealth legal AI startup to hire the first full-time engineer who will own the product from day one. You will select the stack, design data infrastructure, and build the agentic layer that detects and triages legal needs before a client asks.

Collaborating with an in-house legal team, you’ll streamline bottlenecks, set technical standards, and hire the next two engineers, shaping the early engineering culture and delivering a production-grade MVP.