Senior Full-Stack Engineer

Legl; Greater London; On-site; GBP 90,000 - 140,000; Full time

Job summary

Legl is building the operating system for modern legal services. We ship across the entire stack with an AI-first ethos, focusing on automated, reliable, and scalable software that reduces manual work for law firms and regulated businesses.

You’ll influence patterns and production health from day one and own meaningful outcomes. As a Senior Full-Stack Engineer, you’ll work across the stack, design reusable abstractions, and push for rapid iteration without sacrificing quality or trust.

Qualifications

• Experience across the full web stack and ownership from day one.
• Ability to design patterns and abstractions for scalable future work.
• Comfort with using AI to improve engineering outcomes.

Responsibilities

• Work across the whole stack and choose the right layer to solve problems.
• Design patterns and abstractions to make future features cheaper to build.
• Trace recurring issues to root causes and fix the source, not the symptom.
• Maintain production health by addressing noisy systems at the root cause.
• Contribute to the deployment pipeline and CI/CD when needed.
• Use AI and automation to reduce cycle time while preserving quality, safety and trust.
• Own outcomes end-to-end and surface trade-offs to the right decision-maker.

Skills

Full-stack engineering

System design

AI usage

CI/CD

Production health

Cross-functional communication

Job description

Hi We're Legl.

Legl is building the operating system for modern legal services.

We help law firms and regulated businesses replace manual, fragmented workflows with intelligent software from client onboarding and compliance to payments, risk, and reporting.

Legal work is high-stake - it's regulated, complex, and deeply impactful - and our mission is to help regulated firms grow faster, run their businesses more profitably, manage risk intelligently, and deliver great client experiences

We're backed by leading European VCs, scaling quickly, partnered with over 600 law firms including 50 of the UK's top 200, launched in the UK and Australia - and entering our next phase of growth.

We Work Best When

• AI is the central-operating model: not a tool or a future plan - but the way we run.

• Decisions live with people: you're trusted to make calls and own them.

• Think deeply, execute quickly: speed and rigour, not speed or rigour.

The Role

We're a lean, senior engineering team, which means broad scope and real ownership from day one - your work is visibly in the product, not lost in layers of process, and there's no room to hide behind a narrow specialism. We're builders who take an AI-first approach to engineering: we reach for automation and AI to move faster, without dropping the bar on quality, safety or trust.

We're looking for a strong generalist: someone who's comfortable across the whole stack and, more importantly, thinks beyond the features in front of them. Our platform foundations are solid, so the highest-leverage work here isn't in the big pieces - it's in how well we build on them: the patterns, abstractions and operational health that decide whether the next six features are cheap or expensive to build.

You'll ship product. You'll also be the person who leaves the codebase better than you found it, sets the patterns the rest of the team builds on, and gets stuck into the unglamorous work - paying down debt at the root, keeping production healthy - because you know that's what makes everything else faster. We care more about how you think and how you work than about which specific tools you've used; if there's a gap in our stack, we'll cross-train you.

What You'll Do

As the Senior Full-Stack Engineer, you will:

• Work across the whole stack, picking the right layer to solve a problem in.

• Design the patterns and abstractions the team builds on, thinking about the second and third feature, not just the one in front of you, so future work gets cheaper rather than more expensive.

• Trace recurring problems, manual workarounds and support load back to their engineering root cause - and fix the cause, not the symptom.

• Keep an eye on production health: when something's noisy or breaking, you dig to the root rather than muting the alarm, and you leave the fix somewhere the owning team can run with it next time.

• Drop into the deployment pipeline and CI/CD when that's where a problem lives, rather than treating it as someone else's job.

• Use AI and automation with good judgement to reduce cycle time across the team while keeping quality, safety and trust intact.

• Own outcomes end to end - from the decision through release and iteration - and surface trade-offs to the person with the authority to own them, rather than absorbing them yourself.

You’ll be trusted to make decisions and expected to stand behind them.

This Role Is a Great Fit If…

• You're a genuine generalist who's happy moving between layers, and you pick the right place to fix a problem rather than handing it off the moment it crosses into a layer you don't own.

• You think in systems and patterns. You build the reusable thing rather than the one-off, and you care about the engineer who comes after you.

• You go for the root cause. Recurring toil, flaky behaviour and support load are problems to be understood and killed, not worked around.

• You take ownership of outcomes, not just tasks, and you make sound calls when the information is incomplete.

• When you're handed a deadline that isn't realistic, you make the trade-off explicit and get the right person to own it - instead of quietly putting in the hours and calling that delivery.

• You use AI fluently in your own work and are curious about where it genuinely helps the team. We're an AI-native company and you'll have room to push that - we care that you reach for it with judgement, not that you arrive with a portfolio.

• You're a strong communicator who can work across product, support and non-technical stakeholders to deliver high-impact solutions.

This Role Is Not a Great Fit If…

• You want to specialise into one area and stay there, and you hand a problem off the moment it crosses into a layer you don't own.

• You optimise for closing the ticket in front of you and leave the next person to deal with the mess.

• You silently absorb impossible expectations and call that delivery. On a team this small, that single-point-of-failure pattern is exactly what we can't afford.

• You'd rather take tickets and execute tasks than own the outcome, or you treat other teams as ticket-takers.