Senior Backend Engineer (up to £175k)

Dex; Greater London; On-site; GBP 120,000 - 160,000; Full time

Job summary

Dex collaborates with a trusted partner to build an AI-enabled backend platform for handling sensitive financial data in regulated environments. You will architect scalable services and data pipelines, owning end-to-end backend systems and coordinating with ML engineers to productionise models.

This staff-track IC role offers influence across the architecture as the product scales. You will join a senior backend team reporting to founders, driving design decisions, performance optimisations, and

Qualifications

• 7+ years of backend engineering experience in production systems.
• Proficient in Python, FastAPI, and PostgreSQL performance tuning.
• Experience with distributed systems, cloud platforms (Azure), Docker/Kubernetes, and security practices.

Responsibilities

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

Skills

Backend engineering

Python

FastAPI

PostgreSQL

Query optimisation

Distributed systems

Docker/Kubernetes

Azure (cloud)

Security (authn/authz, encryption)

Event-driven architectures

Kafka

Celery

REST APIs

Microservices

SOC 2/GDPR/FCA compliance

Tools

Kafka

Celery

Docker

Kubernetes

Job description

This role is with one of Dex's trusted partner companies. We work closely with their teams to truly understand their culture, goals, and what they're looking for, so we can match you with the right opportunity and give you context about the role before you commit to a process.

Dex is an AI recruiter agent that helps you run your job search. Tell Dex your stack, seniority, and what you want to build. We will manage your applications and surface other opportunities that are a fit.

The role

This company builds an AI workspace for sensitive financial data, serving some of the world's largest regulated institutions. Think workloads where SOC 2, GDPR, and FCA compliance aren't just buzzwords, but fundamental to the product. They've secured significant Series A funding from leading investors and are scaling fast.

You'll join a lean, senior backend team, reporting directly to the founders, at the intersection of AI and finance. This is a staff-track IC seat with visible influence, architecting core services and data pipelines. It's for an engineer who wants to own critical systems end-to-end, not just maintain a small component of a larger platform.

The work

• 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 seamlessly into robust backend systems.
• Lead technical design reviews, mentor engineers, and contribute to shaping the engineering culture as the platform scales.

What You Bring

• 7+ years of backend engineering experience, with a track record of building and scaling production systems.
• Expert-level Python, modern web frameworks (FastAPI), and deep expertise in PostgreSQL query optimisation and scaling.
• Experience with event-driven architectures, message brokers (e.g., Celery, Kafka), and designing clean REST APIs and microservices.
• Strong fundamentals in distributed systems, cloud platforms (Azure preferred), Docker/Kubernetes, and security (authn/authz, encryption).
• Experience shipping software in regulated environments (SOC 2, GDPR, FCA) is a significant advantage.