Staff Backend Engineer - Python, FastAPI | Architecture, Distributed Systems & AI | AI FinTech, Series C | London Hybrid or Remote | Up to £165k + Equity | Work Abroad 90 Days/Year

Staff Backend Engineer - Python, FastAPI | Architecture, Distributed Systems & AI | AI FinTech, Series C | London Hybrid or Remote | Up to £165k + Equity | Work Abroad 90 Days/Year
The Company
We're working with a highly successful, fast-scaling AI b2b FinTech transforming how data and workflows operate across global financial markets.
Following significant growth and Series C funding, they're now heavily investing in new products and international expansion.
The Role | Staff Backend Engineer - Python, FastAPI | Architecture, Distributed Systems & AI | AI FinTech, Series C | London Hybrid or Remote | Up to £165k + Equity | Work Abroad 90 Days/Year
This is a high-impact Staff Engineer position on the IC track, taking ownership of technical strategy and architecture across a complex, rapidly scaling engineering organisation.
Rather than owning a single product or feature set, you'll operate across multiple engineering teams, helping define the architecture and technical direction that underpins the company's next phase of growth.
You'll remain hands-on when it matters, but your impact will extend far beyond your own code - setting engineering standards, solving complex architectural problems and aligning teams around a clear technical vision.
You'll be working across areas including:
Designing and evolving large-scale backend and distributed systems
Defining technical strategy across Platform, AI, Retrieval and shared engineering services
Designing scalable APIs and shared platform capabilities
Leading complex, cross-team technical initiatives from design through to production
Improving reliability, scalability, observability and developer experience
Working closely with AI and Retrieval teams across search, RAG and data-intensive systems
Reducing architectural complexity and establishing common engineering patterns
Contributing hands-on to critical technical work while raising standards through design reviews and mentoring
Using AI-assisted engineering to improve productivity and accelerate delivery
What We're Looking For | Staff Backend Engineer - Python, FastAPI | Architecture, Distributed Systems & AI | AI FinTech, Series C | London Hybrid or Remote | Up to £165k + Equity | Work Abroad 90 Days/Year
Strong experience designing and building large-scale backend systems and distributed architectures
Excellent systems design skills, with evidence of making significant architectural decisions
Experience leading technically complex initiatives across multiple engineering teams
Strong backend programming experience with Python or another modern backend language
Strong experience with AWS, Kubernetes, APIs and modern cloud infrastructure
Comfortable influencing engineering strategy without direct authority
Able to move between high-level technical strategy and hands-on engineering
Strong communication skills with experience mentoring engineers and raising engineering standards
Comfortable making pragmatic technical trade-offs in complex, scaling environments
Experience with AI-powered systems, RAG, search platforms, retrieval systems or vector databases would be particularly valuable.
Experience as a Founding Engineer / CTO, building systems from scratch in an early-stage environment, or modernising complex legacy systems would also be highly relevant.
What's On Offer | Staff Backend Engineer - Python, FastAPI | Architecture, Distributed Systems & AI | AI FinTech, Series C | London Hybrid or Remote | Up to £165k + Equity | Work Abroad 90 Days/Year
Up to £165,000 base salary + equity
Pension contribution matched up to 7%
Private medical insurance
Flexible hybrid or remote working
Work abroad for up to 3 months per year
25 days' holiday + public holidays
Professional learning & development budget
1-month paid sabbatical after 5 years
Significant influence over the architecture and technical direction of a rapidly scaling engineering organisation
Staff Backend Engineer - Python, FastAPI | Architecture, Distributed Systems & AI | AI FinTech, Series C | London Hybrid or Remote | Up to £165k + Equity | Work Abroad 90 Days/Year
This is an opportunity for a genuine Staff-level Backend / Platform Engineer who enjoys solving difficult systems problems, influencing architecture across multiple teams and remaining close enough to the code to lead by example.

Work arrangement
Yes