Principal Engineer

Oliver Bernard; Greater London; On-site; GBP 243,000 - 297,000; Full time

Job summary

Oliver Bernard is seeking a Principal Engineer in London to join a high-growth YC-backed AI startup. The role is hands-on and focused on scalable backend systems at scale, reporting to the Head of Engineering and CTO/Co-Founder.

You will drive architecture and delivery as the company grows from Series A through expansion. Candidates should have a computer science background, a proven track record of scaling products, and real hands-on Python experience.

Qualifications

• Computer science background.
• Experience taking companies from Series A through to Series C.
• Hands-on Python experience.

Responsibilities

• Scale backend systems to handle growth.
• Collaborate with Head of Engineering and CTO/Co-Founder to drive scale and architecture.
• Diagnose hard problems and fix them to unlock the next phase of growth.
• Contribute hands-on engineering work to deliver impact from day one.

Skills

Python

Job description

Principal Engineer - Series A Scale Up - Up to £270,000

I'm currently looking for a Principal Engineer to join a high-growth, YC-backed AI startup based in London.

It's a hands-on IC role focused primarily on scalable backend systems and genuinely at scale.

You'll be working directly with the Head of Engineering and CTO/Co-Founder — your impact will be visible and felt from day one. They're looking for someone who has taken companies from Series A through to Series C on multiple occasions; someone who has walked into complex, high-pressure environments, diagnosed the problems, fixed them, and unlocked the next phase of growth. This is about scaling products, not just teams.

Working Arrangements:

3 days per week in Central London office

Why it might interest you

• YC-backed and scaling fast, adding 10 heads to engineering over the next few months
• Real AI in production (not just R&D)
• Smart, driven team of builders — ex-Meta, Spotify, MIT, and high-growth startups
• Large Series A investment already secured + up to 9 million in ARR

Ideal profile

– Computer science background

– Strong, demonstrable signal of impact in previous roles

– Experience taking companies from Series A through to Series C

– A track record of fixing hard systems problems that unlocked scale

– Have real hands-on Python experience

Principal Engineer - Series A Scale Up - Up to £270,000