Founding Engineering Lead (up to £250k)

Dex; Greater London; On-site; GBP 120,000 - 180,000; Full time

Job summary

Dex's partner company is seeking the first technical hire to architect and build an AI-native legal service platform from scratch. You will own the MVP, define architecture, and recruit the founding engineers, working directly with a non-technical founder and senior lawyers.

You will lead the core stack decisions, integrate with Slack, Notion, email and CRMs, and establish engineering culture and quality standards while taking on hands-on coding and shaping product direction in a highly

Qualifications

• Track record of shipping production-grade AI-native or agentic products from zero to one within a venture-backed startup.
• Staff-level systems and software engineering judgement, including experience building deep integrations into platforms like Slack, Notion, email, or modern CRMs.
• A pragmatic builder mindset with proven ability to scope tight MVPs, ship without over-engineering, and back architectural trade-offs with clear reasoning.

Responsibilities

• Architect and build the core agentic platform from scratch, enabling proactive triage, context gathering, and workflow automation across tools like Slack, Notion, and CRM systems.
• Make every foundational stack and infrastructure decision, balancing rapid MVP velocity with the reliability and security required of a regulated firm taking full liability for its output.
• Sit alongside elite in-house lawyers and active design customers to translate ambiguous legal processes into deterministic, highly automated production workflows.
• Recruit, interview, and onboard the founding engineering team while establishing engineering culture, code quality standards, and technical direction.

Job description

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.

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

Most legal AI startups sell software to legacy law firms, leaving the client with the same slow, expensive service while the firm pockets the margin. Backed by a $7m pre-seed from top-tier European tech investors and founders, this stealth startup flips the model by launching as an AI-native, fully regulated legal service. Their agentic layer embeds directly into customer workspaces like Slack, Notion, and email to proactively catch legal needs and automate 90% of the prep work, with elite in-house lawyers providing final judgement, sign-off, and liability.

As the first technical hire, you will own architecture, the initial product build, and technical hiring from an entirely clean slate. This is a true zero-to-one builder role, not a maintenance gig or a hands-off management track. You will partner directly with an experienced non-technical founder and veteran corporate lawyers to decide what to automate first, define the MVP, and recruit the founding engineers who join after you.

The work

• Architect and build the core agentic platform from scratch, enabling proactive triage, context gathering, and workflow automation across tools like Slack, Notion, and CRM systems.
• Make every foundational stack and infrastructure decision, balancing rapid MVP velocity with the reliability and security required of a regulated firm taking full liability for its output.
• Sit alongside elite in-house lawyers and active design customers to translate ambiguous legal processes into deterministic, highly automated production workflows.
• Recruit, interview, and onboard the founding engineering team while establishing engineering culture, code quality standards, and technical direction.

What You Bring

• Track record of shipping production-grade AI-native or agentic products from zero to one within a venture-backed startup.
• Staff-level systems and software engineering judgement, including experience building deep integrations into platforms like Slack, Notion, email, or modern CRMs.


• A pragmatic builder mindset with proven ability to scope tight MVPs, ship without over-engineering, and back architectural trade-offs with clear reasoning.


• Experience setting technical direction, hiring, and mentoring other engineers, paired with a commitment to staying predominantly hands-on in the codebase.