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

Owen Thomas | B Corp™

Greater London

Hybrid

GBP 99,000 - 165,000

Full time

2 days ago

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Benefits offered by this job

Pension contribution matched up to 7%

Private medical insurance

Flexible hybrid or remote working

Work abroad for up to 3 months per yr

25 days' holiday + public holidays

Professional learning & development预算

1-month paid sabbatical after 5 years

Job summary

AI FinTech in London is seeking a Staff Backend Engineer to own technical strategy and architecture across a scalable, AI-powered platform. You’ll work across teams, setting standards, and guiding architectural decisions while remaining hands-on when needed.

The role spans Platform, AI, Retrieval, and shared services with a strong emphasis on scalable APIs and reliability. You’ll lead cross-team initiatives, mentor engineers, and help define the technical vision for rapid growth.

Qualifications

Strong experience designing and building large-scale backend systems and distributed architectures.
Excellent systems design skills with evidence of architectural decisions.
Experience leading technically complex initiatives across multiple teams.
Strong backend programming experience with Python or another modern language.
Experience with AWS, Kubernetes, APIs and modern cloud infrastructure.
Able to influence engineering strategy and mentor engineers.

Responsibilities

Designing and evolving large-scale backend and distributed systems.
Define technical strategy across Platform, AI, Retrieval and shared services.
Design scalable APIs and shared platform capabilities.
Lead complex, cross-team technical initiatives from design to production.
Improve reliability, scalability, observability and developer experience.
Collaborate with AI and Retrieval teams on search and data-intensive systems.
Reduce architectural complexity and establish common engineering patterns.
Contribute hands-on to critical technical work and mentor others.
Use AI-assisted engineering to improve productivity and delivery.

Skills

Backend design

Distributed architectures

Python

AWS

Kubernetes

APIs

Cloud infrastructure

Mentoring

Technical strategy

Hands-on engineering

Tools

Python

AWS

Kubernetes

APIs

Job description

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.

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

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.

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 yearsSignificant influence over the architecture and technical direction of a rapidly scaling engineering organisation

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.

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