Engineering Team Lead - 12 month FTC

Flagstone Group

Greater London

On-site

GBP 100,000 - 150,000

Full time

14 days+

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Benefits offered by this job

Hybrid working

Competitive bonus

Flexible benefits budget

Salary sacrifice options

Around the World scheme

Mental wellbeing support

Learning and development budget

Private health care

Medical cash plan

Life insurance

Pension matching

25 days holiday

Enhanced Parental Leave

Job summary

Flagstone in London is seeking a hands-on Engineering Lead with around 10 years' experience to run the Banks squad on the Bank Portal, moving from migration to a commercial engine for partnerships.

You'll own technical direction, quarterly roadmap, and people management, balancing risk, data isolation, and agile delivery, with strategic input across the tribe.

Qualifications

Strong commercial C#/.NET experience.
RESTful API design and SQL skills.
Cloud-native Azure development.
Frontend review of React/TypeScript work.
TDD in practice (NUnit, MSTest, Playwright/Selenium).
Experience with agentic development tools (Claude Code or similar).
Comfort in regulated/data-sensitive environments with per-bank isolation and audit logging.

Responsibilities

Own the squad's technical direction and quarterly roadmap.
Drive the commercial features on the migrated foundation.
Manage day-to-day delivery and performance; handle underperformance and exits.
Collaborate across the tribe; contribute to engineering-wide standards.

Skills

C#/.NET

RESTful APIs

SQL

Azure

React/TypeScript

TDD

Code tooling

Data isolation

Agile / decision-making

People management

Stakeholder management

Coaching engineers

Job description

What is Flagstone?

Flagstone is many things. An online savings platform, reinventing how individuals, businesses, and charities manage, protect, and grow their cash. A diverse group of people, bound by a collaborative spirit, and shared purpose. And lastly, a thriving, profitable business - where smart people do their best work.

A feel for our culture:

To revolutionise the savings market, we need to be at our best. But high performance takes more than talent - it takes a culture of kindness, respect, and growth.

That’s why we’re building a diverse, inclusive community, where your voice is heard and valued. Where, with close support and room to develop, you can surpass even your own expectations. And be rewarded for it.

We may not change the world, but we can change the world of financial technology. And all it takes is a winning mix of drive, talent, and empathy. Our culture celebrates all three.

But enough about us. Let’s talk about you.

Does this sound like you?

You're a hands‑on Engineering Lead, ideally with around 10 years' experience, ready to run a squad with real autonomy. You'll lead the Banks squad on the Bank Portal, the partner-facing application our banking partners use to view and act on their Flagstone relationship. By the time you start, the squad will have delivered the foundational rebuild (migrating banks off the legacy tool to full feature parity), and you'll pick up the next phase: building the commercial capability on top of that foundation and turning the portal into a genuine commercial engine for the partnership.

This is a full-stack squad (.NET backend, React/TypeScript frontend) working in a regulated, data-sensitive environment, so the role carries real weight: partner-facing delivery, strict data isolation between banks, and the judgement calls that come with both.

What you’ll do:

You’ll own the squad's technical direction and quarterly roadmap, not just participate in it, driving the commercial features that build on the migrated foundation (self-serve rate changes, new product submissions, liquidity data) while keeping the newly‑migrated platform stable and any remaining cohorts or legacy decommissioning on track. You'll make most technical debt and risk calls autonomously, escalating only where tribe-level coordination is genuinely needed.

On people, you'll run day‑to‑day delivery and performance management, including the harder conversations, handling underperformance and any exits directly rather than deferring them upward. Within the FTC's 12 months, expect the emphasis to sit more on driving commercial delivery at pace than on longer‑term development pathways, though coaching engineers and creating stretch opportunities is still part of the job.

You'll also work as a peer across the tribe: contributing to engineering-wide standards, comparing notes with other Team Leads, and representing the squad's constraints and progress in tribe-level planning.

What you’ll bring:

We're a Microsoft shop: C#/.NET is our core backend language, on Azure, cloud‑first. The Bank Portal specifically runs on .NET (Aspire, Duende BFF, YARP) with a React/TypeScript frontend, so while backend depth is the priority, comfort reviewing across a full‑stack architecture matters more here than on a purely backend squad.

Strong commercial C#/.NET experience, with a solid grasp of SOLID, event‑driven architecture and DDD

RESTful API design and SQL skills

Cloud‑native Azure development

Enough frontend fluency to review React/TypeScript work, even if you're not hands‑on day to day

TDD in practice (NUnit, MSTest, Playwright/Selenium or similar)

Experience with agentic development tools (Claude Code or similar)

Comfort working in a regulated or data‑sensitive environment, this squad enforces strict per‑bank data isolation and audit logging as a core part of the architecture

Comfort working in an agile environment, and being the final escalation point for decision making

An ability to assess and weigh risk, making sound, defensible decisions rather than deferring by default

And on the people side:

A track record of direct, fair performance management, including the difficult conversations

Confident stakeholder management, and the ability to translate technical trade‑offs for non‑technical audiences

Genuine enthusiasm for coaching and developing engineers

Proactive, collaborative problem‑solving

How we reward you:

At Flagstone, the benefits extend beyond false gifts like "fruit and snacks". Instead, we invest in your health, wealth, and professional development. Here’s a selection of our benefits:

Hybrid working - Spend at least 1 day a week with your team in our collaborative London office

Competitive bonus scheme - designed to reward and recognise high performance

Flexible benefits budget - a pot to fund meaningful benefits for you, whether it's hormone or fertility testing, cancer screening, neuro-diversity coaching or something that matters for you.