Senior Backend Engineer - AI-Driven Finance APIs (Remote)

Ersilia

Greater London

Hybrid

GBP 90,000 - 150,000

Full time

14 days+

Application generator

Turn this role into an interview — a resume and cover letter built around what this employer wants.

Get past ATS filters

Job summary

Ersilia in London is seeking a Senior Backend Engineer to build production Python backends (FastAPI) powering AI features for professional investors. You will own APIs, design orchestration for agentic workflows, and work with PostgreSQL and ClickHouse, shipping features from sketch to live production.

The team is small and highly impactful, with opportunities to mentor others, influence architecture, and collaborate closely with founders.

Qualifications

5 to 15 years of backend engineering experience, most of it in Python, in production environments.
A track record of building and personally owning APIs or services used by real customers.
Time spent at a startup or scaleup (roughly 30 to 100 people).
Hands-on experience shipping AI or LLM features to production: agentic workflows, RAG, or tool use.
Strong SQL and PostgreSQL or an equivalent relational database.
A genuine preference for staying hands-on and coding day to day.

Responsibilities

Build and ship production backend services and APIs in Python (FastAPI).
Design and own the orchestration layer for agentic AI capabilities.
Work with PostgreSQL and ClickHouse for fast data retrieval.
Take ideas from founders and ship features to production within the same sprint.
Mentor teammates and help set engineering standards as the team scales.