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- Tasks: Lead architecture decisions and mentor teams to build impactful fintech solutions.
- Company: Join a mission-driven fintech transforming finance for small businesses in the UK.
- Benefits: Enjoy remote work, 25 days holiday, life assurance, and discounts with top retailers.
- Why this job: Shape the future of finance while making a real difference for 5.5 million SMEs.
- Qualifications: Must have 2+ years as a Principal Engineer or similar role with SaaS experience.
- Other info: Flexible remote-first role with opportunities for London meetups and team events.
The predicted salary is between 43200 - 72000 £ per year.
We’re working with a mission-driven fintech that’s solving a massive problem: small businesses — the backbone of the UK economy — are still underserved by traditional finance. This company is changing that, helping banks and lenders make faster, smarter, fairer credit decisions using real-time financial data.
Already trusted by 80+ major banks and lenders, they are scaling fast — and now they’re looking for a Principal Engineer to shape the next stage of their platform and lead from the front.
Why This Role is Great
- You’ll architect the core of the platform used by major UK banks and lenders
- Get in early enough to influence big decisions — but with real traction already proven
- Work across multiple product teams, mentoring, guiding, and building alongside them
- Blend strategy and code — be the go-to technical voice in the room
- Remote-first with the flexibility to come together in London when it counts
- Genuinely meaningful work: better finance access for 5.5 million UK SMEs
What You’ll Be Doing
- Lead architecture decisions and make them real — from developer-friendly APIs to scalable platform components
- Guide cross-functional teams (frontend, backend, QA) with your experience and technical instincts
- Collaborate closely with product, design, and commercial teams to build solutions that actually solve real problems
- Balance pragmatism with perfection — make things work first, then make them beautiful
- Mentor senior engineers and help scale a top-class team
- Be a visible, respected voice across the business, bringing clarity and confidence to complex tech questions
- Help shape hiring, team growth, and long-term engineering strategy
Tech Snapshot
- Languages: Java, Kotlin, JavaScript
- Frontend & Frameworks: React, Spring, Temporal
- Databases: PostgreSQL, MongoDB
- Cloud: AWS (heavy use), with IaC (Terraform)
- Practices: TDD, CI/CD, clean architecture, pragmatic testing
- Bonus Points: Data engineering or machine learning experience
What They’re Looking For
- A Principal Engineer, Tech Lead, or Software Architect with at least 2 years at this level
- You’ve built and scaled SaaS platforms — ideally in fintech or data-heavy domains
- You’re a hands-on problem-solver who can step back, see the big picture, and then guide others through it
- You’re confident working with stakeholders from execs to product managers — turning complexity into clarity
- You care deeply about engineering craft, team health, and customer impact
- You can mentor senior engineers and inspire confidence across the org
Perks & Benefits
- Remote-first role with London-based meetups (office in Shoreditch)
- 25 days holiday + public holidays
- Life assurance (4x salary)
- Pension contribution
- Virtual GP & wellbeing support
- Perks & discounts with top retailers (ASOS, Tesco, Amazon, etc.)
- Referral bonus scheme
- Regular socials & team events
Ready to Lead with Purpose?
If you are a Principal Engineer who loves shaping product direction, building great tech, and mentoring high-performing teams — this is your moment to lead from the front and make a difference. Message me for a confidential chat or send over your CV — let’s talk.
Contact Detail:
numi Recruiting Team
StudySmarter Expert Advice 🤫
We think this is how you could land Principal Engineer
✨Tip Number 1
Familiarise yourself with the fintech landscape, especially focusing on how small businesses interact with financial services. Understanding the unique challenges SMEs face will help you articulate your vision for their future during discussions.
✨Tip Number 2
Showcase your experience in building and scaling SaaS platforms by preparing specific examples of past projects. Be ready to discuss how you’ve led architecture decisions and mentored teams, as this role heavily emphasises leadership.
✨Tip Number 3
Engage with the company’s existing products and services. By understanding their current offerings, you can propose innovative ideas that align with their mission and demonstrate your proactive approach during interviews.
✨Tip Number 4
Network with professionals in the fintech space, particularly those who have experience with SMEs. This can provide valuable insights and potentially lead to referrals, which can significantly boost your chances of landing the job.
We think you need these skills to ace Principal Engineer
Some tips for your application 🫡
Tailor Your CV: Make sure your CV highlights relevant experience in building and scaling SaaS platforms, particularly in fintech or data-heavy domains. Emphasise your hands-on problem-solving skills and any leadership roles you've held.
Craft a Compelling Cover Letter: In your cover letter, express your passion for improving finance access for SMEs. Discuss how your technical expertise aligns with the company's mission and how you can contribute to their goals.
Showcase Technical Skills: Clearly outline your proficiency in the required technologies such as Java, Kotlin, and AWS. Mention any experience with TDD, CI/CD, and clean architecture, as these are crucial for the role.
Highlight Mentorship Experience: Since the role involves mentoring senior engineers, include examples of how you've guided teams in the past. This will demonstrate your ability to inspire confidence and foster team health.
How to prepare for a job interview at numi
✨Understand the Company’s Mission
Before your interview, make sure you grasp the company's mission to support SMEs in the UK. Familiarise yourself with how their technology is making a difference in the finance sector, as this will show your genuine interest and alignment with their goals.
✨Showcase Your Technical Expertise
Be prepared to discuss your experience with the tech stack mentioned in the job description, such as Java, Kotlin, and AWS. Highlight specific projects where you've led architecture decisions or built scalable platforms, as this will demonstrate your hands-on capabilities.
✨Prepare for Leadership Questions
As a Principal Engineer, you'll be expected to lead teams and mentor others. Think of examples from your past where you've successfully guided cross-functional teams or mentored junior engineers, and be ready to share these stories during the interview.
✨Balance Pragmatism with Perfection
The role requires a balance between getting things done and ensuring quality. Be ready to discuss how you've approached this in previous roles, perhaps by sharing instances where you prioritised functionality first before refining the details.
