Staff Backend Engineer – AI Finance & Scalable Systems

Dex; Greater London; On-site; GBP 90,000 - 130,000; Full time

Job summary

Dex is partnering with a leading fintech to hire a senior backend engineer. You will join a lean, senior backend team, reporting directly to the founders, at the intersection of AI and finance. This is a staff-track IC role with influence, architecting core services and data pipelines.

You’ll own end-to-end systems, mentor engineers, and collaborate with ML teams to productionise models and ensure robust backend integration as the platform scales.

Qualifications

• 7+ years backend engineering experience building production systems.
• Expert Python, FastAPI, and PostgreSQL optimisation for scalable apps.
• Experience with event-driven architectures and microservices.
• Strong knowledge of distributed systems, cloud platforms, and security.
• Experience shipping in regulated environments is a plus (SOC 2, GDPR, FCA).

Responsibilities

• Architect and build scalable backend services and APIs for an AI workspace handling sensitive financial data.
• Design and implement high-performance data pipelines to process large-scale financial datasets with strict accuracy and latency requirements.
• Optimise database schemas, queries, and indexing strategies for PostgreSQL in a high-throughput, distributed environment.
• Partner with ML engineers to productionise models, integrating them into robust backend systems.
• Lead technical design reviews, mentor engineers, and shape engineering culture as the platform scales.

Skills

Backend engineering

Python

FastAPI

PostgreSQL

Distributed systems

Docker/Kubernetes

Security

Tools

Kafka

Celery

Azure

Job description

Dex is partnering with a leading fintech to hire a senior backend engineer. You will join a lean, senior backend team, reporting directly to the founders, at the intersection of AI and finance. This is a staff-track IC role with influence, architecting core services and data pipelines.

You’ll own end-to-end systems, mentor engineers, and collaborate with ML teams to productionise models and ensure robust backend integration as the platform scales.