Confidential company, Engineering
Principal Software Engineer at well-funded fintech platform
- Location
- London, United Kingdom
- Compensation
- £120k-£145k
Are you a senior engineer who thrives on solving complex architectural puzzles where data correctness is paramount? This well-funded fintech is looking for a Principal Software Engineer to own the technical direction of a platform modernizing global financial workflows.
You’ll design high-scale systems handling millions of transactions using NestJS and cloud infrastructure, moving toward an advanced software lifecycle that maximizes engineering leverage. This is a high-impact, senior IC role in London offering the chance to shape the core architecture of a rapidly growing startup. If you want to build mission-critical systems with a high-trust, low-ego team, this is the perfect opportunity.
What's the next step?
Confidential company are hiring from Jack's network. Talk to Jack for free and get a direct introduction to the team, if a good fit.
Role overview
You will lead the technical direction and architecture of a high-scale financial platform modernizing complex payment and settlement workflows. Managing millions of transactions, you’ll design robust backend systems using NestJS and cloud infrastructure, ensuring high correctness and operability. This senior IC role focuses on technical excellence, architectural leadership, and scaling mission-critical data infrastructure within a well-funded, growth-stage startup.
About the company
Well-funded fintech platform
What you will do
- Design and oversee the architecture of a modular backend platform, prioritizing idempotency, failure isolation, and sophisticated event-driven workflows.
- Bridge the gap between product strategy and technical execution by designing version-aware APIs and high-performance data processing systems.
- Mentor engineering teams through design reviews and technical leadership while remaining deeply hands-on with the core system architecture.
Who this is a fit for
- Extensive experience building and scaling complex backend systems using modern JavaScript/TypeScript frameworks and Node.js in high-traffic environments.
- Deep expertise in cloud-native infrastructure and relational database design, particularly for high-volume, transactional, and regulated data.
- Strong architectural thinking with a track record of implementing distributed systems patterns, failure recovery strategies, and clean service boundaries.
Why this role is remarkable
- Take deep technical ownership of a platform where data correctness is critical for financial settlements and large-scale transaction management.
- Join a well-funded startup backed by leading venture capital firms, currently scaling its operations to transform traditional financial processes.
- Work at the forefront of engineering innovation, leveraging modern AI-assisted development lifecycles to solve sophisticated architectural challenges.
How Jack & Jill work together
What happens next?
Jack’s an AI agent for job searching and career coaching. He works for you.
Jill is the AI agent for hiring, working for the company. She recruits from Jack’s network.
If your profile’s a match and Confidential company wants to meet, Jill will make the intro. In the meantime, Jack will send you excellent alternatives.