Principal Engineer

FundApps; City Of London; Hybrid; GBP 120,000 - 140,000; Full time

Benefits offered by this job

Health insurance

Pension

Learning budget

Holiday leave

Volunteer leave

Job summary

FundApps is seeking a Principal Engineer in London to set technical direction for our Surveillance estate. You will stay hands-on—review architecture, write code, join incidents—and collaborate with senior engineers to raise the bar on reliability, security and craft.

You will balance deep technical work with a 10,000-foot view, guiding teams, defining interfaces, and ensuring cost-conscious, scalable production systems across AWS and Azure.

Qualifications

• Hands-on senior engineer with deep systems knowledge across large-scale platforms.
• Experience in distributed systems, data platforms, or cloud environments is essential.

Responsibilities

• Set technical direction across the Surveillance estate and mentor senior engineers.
• Review architecture, read/write code, and participate in incidents.
• Ensure reliability, observability and operational correctness across the platform.
• Drive architectural coherence and security architecture decisions.

Skills

Distributed systems

System design

Leadership

Code reviews

Tools

AWS

Azure

Kubernetes

Terraform

Helm

GitOps

Job description

Principal Engineer

Department: Engineering

Employment Type: Full Time

Location: London, UK

Reporting To: David Haines

Compensation: GBP 120,000 - GBP 140,000 / year

Description

SteelEye, now merged with FundApps, provides communications, trade and order surveillance to some of the world's largest financial institutions.

As a Principal Engineer you will set technical direction across the Surveillance estate and work through our most senior engineers on its hardest problems.

We deliver enterprise SaaS to hundreds of clients, many of them running the same platform under very different regulatory, security and scale expectations, and doing that well is an engineering problem in every layer rather than an operational one. Delivery sits with the teams building our products. What sits with you is whether the whole thing holds together: whether the architecture is coherent, whether the standard of engineering craft is rising, whether the security model makes sense end to end, whether we know production is working, and whether our most senior engineers are getting better.

Our clients expect strong technical assurance and our platform runs across AWS and Azure. The decisions you influence determine how safely teams can make changes, how quickly we can activate clients and how efficiently we can operate.

This is a Principal role with real leadership attached, and it stays technical. You will stay hands on: reviewing architecture, reading and writing code, and joining incidents. The role moves between deep technical detail and a 10,000 foot view, often on the same day.

What You'll Be Working On

Reliability, observability and operational correctness

The priority is not simply whether the platform is up, but whether it is doing its job: client feeds arrive completely, surveillance runs against the right window and expected alerts fire.

You and the team will establish patterns for correctness monitoring, escalation, incident response and disaster recovery, allowing product teams to define their own alerts, service levels and response playbooks

Software craftsmanship and change safety

Alongside correctness, change safety is our other top engineering priority: the ability to change the platform frequently, in small increments, with confidence that nothing has quietly broken. That means tests that earn trust, reviews that catch design problems rather than typos, deployment that is boring, and the discipline to keep it that way under pressure.

You will own the standard of engineering craft across Surveillance: what good looks like, how it is taught, and whether it holds when nobody is watching.

Architectural coherence

Each team will make sensible local decisions. Your job is to make sure they add up: that we are not solving the same problem three ways, that the interfaces between domains are deliberate, and that the estate can still be reasoned about in two years.

You will set the technical direction others plan against, including how client environments are managed across their lifecycle and how software reaches production.

Security architecture

Not governance, which sits with our Security team, but the engineering picture: how client environment isolation actually works, where the boundaries are, how privileged access is granted and removed, and which risks we have consciously accepted. This includes workload identity, SCIM 2.0 and enterprise identity integration for client provisioning.

Individual teams will secure their own patch. Somebody has to own how it fits together. Security policy, SOC 2 and ISO 27001 certification, the security risk register and the compliance programme are owned by our Security team. You own the engineering controls and technical evidence they depend on, working closely with Security rather than running a compliance function, and without becoming an approval gate.

Growing our senior engineers

A Principal here is measured partly by the engineers around them. That means growing their scope rather than directing their work: helping them take on problems larger than a single team, raising the standard of design review and technical writing, and building a bench that does not route through you.

Cost and unit economics

Cloud cost grows as we add new clients, so it needs to be an engineering concern.

You will work with the teams building our products and our FinOps engineering effort to improve optimisation, capacity strategy and client-level cost visibility. Cost is a shared responsibility, not something owned in isolation.

Enterprise client assurance and commercial support

You will help turn technical assurance around areas such as environment segregation, promotion controls, change management, data residency and disaster recovery into repeatable capabilities rather than bespoke exercises.

You will also review deals for technical risk and represent our architecture with client CISOs and technical stakeholders.

What success looks like

The technical direction is already established. You will inherit goals in flight and formulate plans to deliver the desired outcomes.

We want someone who can get close to the full technology environment and team quickly, build on what is working and move at pace rather than returning to first principles.

Success means teams can move safely and faster because of the platform and the standards, with less operational toil and a growing proportion of engineering time spent on elective work rather than keeping the lights on.

That means:

• Client onboarding becomes increasingly automated end to end.
• Observability lets teams answer common operational questions without elevated production access.
• Change is frequent, small and reversible, and incidents do not scale with deployment frequency.
• Product teams have better visibility into client-level cost and margin.
• Each area has clear ownership and no single person becomes a dependency, including you.
• Our most senior engineers are operating at greater scope than when you arrived.

What You'll Bring To The Team

You have depth somewhere real and it doesn't necessarily have to be ours:

• We are not looking for a specialist in one layer.
• You might have built your reputation in distributed systems, data platforms, application and product engineering, machine learning, or platform and infrastructure.
• What matters is that somewhere in the stack you went deep enough to earn the respect of very good engineers, and that you can bring that judgement to areas where you are not the expert.

You have a track record of hands‑on, material impact. Not architecture decks, and not delivery you delegated:

• Things you personally designed, built, or unblocked by getting into the detail, where the outcome mattered commercially and you can explain both the mechanism and the tradeoffs you accepted.

You have enough breadth to challenge a specialist:

• You will be accountable for areas where someone closer to the work knows more than you do.
• You should be able to ask the question that exposes the weak assumption, and to recognise when you are being told what you want to hear.

You have led senior engineers:

• You know how to give strong people meaningful ownership rather than routing decisions through yourself.
• You can name engineers whose trajectory changed because of you.

You have raised the engineering standard of teams beyond your own.

• You have opinions about testing, review and change safety that you have actually implemented, and you can tell the difference between a team that has adopted the practices and one that has adopted the vocabulary.

You are comfortable working across distributed engineering centres, and you know that raising craft at distance happens through pairing and review rather than through standards documents.

• You have measurably improved how quickly other engineers ship, through paved paths, faster feedback and removing the need to understand internals in order to work safely.

You understand security as engineering controls rather than process, including identity and access management, privileged access, workload identity and client environment isolation.

• You are comfortable working in environments where enterprise customers expect technical assurance and can hold your own with a client CISO.

You are equally comfortable moving between architecture, code, incidents, client conversations and commercial considerations.

AWS and Azure Kubernetes and EKS Terraform Helm GitOps CI/CD Elasticsearch Kafka PostgreSQL ClickHouse Python services observability and Prometheus multi-fleet, multi-cell client environment architecture cloud and Kubernetes security

Nobody knows all of it well. You should recognise most of it and be genuinely deep in some of it.

You think in systems, and you treat reliability, security and developer productivity as the same engineering problem rather than three competing ones. You prefer automated guardrails to manual approvals, paved paths to documentation and evidence to assertion.

You are credible in a board conversation and credible in a code review, and you do not treat those as different people.

A Few Things To Know Before You Apply

Salary

The salary for this role is between GBP 120,000 to GBP 140,000 and the final offer will be based on your skills and experience.

Work Eligibility

We require candidates to have permission to work in the UK without visa sponsorship.

We work hybrid and ask that new FundAppers spend 3 days per week at our shiny London office during their first 6 months, to make the most of getting to know the business and other FundAppers.

After that, our policy is at least 2 days per week in the office to collaborate, connect and enjoy our shared space and team activities.

Life at FundApps

Work/life balance with flexible hybrid working

Wellbeing benefits such as private health insurance, life insurance, a flexible stipend and mental health coaching

Matched pension contribution up to 10%

Peer micro-bonuses through Bonusly

GBP 1,000 learning budget each year and unlimited professional development leave

Peer-led 'Brown-bag lunch' learning sessions and an annual Learning Festival

25 days holiday leave + an extra day next year if you use it all + an extra day after 3 & 5 years

5 Years @ FundApps - additional 4 weeks paid holiday leave during your 5th year as a FundApper

26 weeks leave for all new parents regardless of gender, location or family structure

Volunteering leave

Birthday off

We are proud of the diversity of all FundAppers - it makes us strong. We provide flexibility around religious observances and embrace a variety of cultural celebrations! If you're looking for a workplace where you can just be yourself, you're in the right place.

Your Privacy

Any information you submit through our job application process will be used for the purposes of assessing your fit for a role at FundApps. We may also retrieve and store information from your public social media profiles for the same purpose. By applying for this position, you consent to your data being processed in accordance with the FundApps privacy policy.