Client Server

Backend Software Engineer Python - Technologist

AI C++ Cybersecurity Python Rust

Backend software engineer joining a Cambridge-based cybersecurity company that uses AI to protect clients worldwide from advanced cyber threats. The role focuses on backend development in Python, with Rust and C++ also central to the stack; salary up to £80k.

up to 80K £

Data Engineer Python Sql Spark

UKFull-time

Azure C# Databricks Python Spark +2 skills

Data Engineer at a $17bn+ hedge fund in London (Soho), joining a small team that sources, combines, and transforms third-party market data for traders, quants, and the investment desk. Core stack is Python/C#, SQL, with Apache Spark and Azure Databricks preferred; salary to £160k plus bonus.

up to 160K £

Real-Time Backend Engineer (Go/Node Pub/Sub) - Remote + Equity

Distributed Systems Node.js Slack

Builds and owns the backend of a real-time messaging platform in Go and Node.js, designing scalable distributed pub/sub systems with a focus on performance and reliability. Mostly remote with occasional London office meetups, Slack collaboration, and monthly tech talks.

Backend Engineer - C# .NET Core | FinTech (Newcastle)

C# Distributed Systems .NET Fintech SDLC

Backend engineer building high-performance C# .NET Core services and distributed systems that handle large data volumes for a FinTech client, onsite in brand-new Newcastle offices. The role covers the full SDLC with flexible hours and a focus on quality, robust software.

up to 130K £

Backend Developer Golang Node Pub / Sub

AI Cloud Distributed Systems Event Driven Architecture Go +5 skills

Backend Developer building the core real-time messaging platform of a high-growth tech company, designing scalable pub/sub and distributed systems in Go or Node.js. Mostly remote with monthly meetups at a dog-friendly North London office, plus work on low-latency messaging and AI communication infrastructure.

up to 120K £

Java Developer AI Claude - FinTech

AI C++ Fintech Java Multithreading

Hands-on backend Java role at a scaling FinTech in Newcastle, modernising a C++ trading system into a scalable, high-performance real-time Java platform for Front Office traders. Involves architectural ownership and use of AI-assisted tools like Claude; salary up to £120k plus bonus.

up to 120K £

Python Software Engineer Machine Learning Aws

RemoteUK

Agile AWS Databricks Design Patterns Machine Learning +6 skills

Senior hands-on Python engineer at a European car insurance tech company, joining a cross-functional team to implement machine learning algorithms into production underwriting and pricing systems. Core stack is Python, AWS and ML tooling (Databricks, PostgreSQL, Redshift, MLflow); fully remote within England, salary up to £90k.

up to 90K £

Python Software Engineer Conversational AI

RemoteUK

AI AWS Conversational AI Infrastructure as Code LLM +3 skills

A remote, hands-on engineer role designing and building production-grade AI systems and backend services for a conversational AI platform. Day to day you work with Python, LLMs, AWS, TypeScript, Node.js and infrastructure as code, owning technical decisions and evolving the architecture.

Software Engineer Python SQL - Market Data

CI/CD Data Engineering Data Lake Distributed Systems ETL +6 skills

A hands-on Python engineer builds and maintains components of a financial market-data platform: designing ETL pipelines, data lakes/lakehouses and distributed microservices, while improving infrastructure, CI/CD and observability. Core stack is Python and SQL with relational, NoSQL and columnar databases.

up to 150K £

Python Developer – Data Platform & ETL (London)

CI/CD Data Quality ETL Microservices Observability +1 skills

A Python developer at a London hedge fund builds and optimises a data platform, working on ETL pipelines, microservices, and databases with a focus on data quality and reliability. The role involves CI/CD workflows, code reviews, and supporting logs, monitoring, and observability.

Python Developer / Team Lead - FinTech

HybridUKLead

API AWS Azure CI/CD Cloud +7 skills

Hands-on Team Lead for a core banking platform at a well-funded FinTech in London: split roughly 50/50 between hands-on Python/FastAPI architecture, refactoring and feature delivery, and leading/mentoring a small team. Stack is Python with FastAPI APIs, cloud (GCP preferred), and CI/CD.

React Developer Senior / Lead

UKLead

API JavaScript React Redux TypeScript

Hands-on Lead React Developer owning the frontend of a core product at a scale-up: leading front-end architecture, integrating APIs and real-time data, setting tooling and build pipelines, and mentoring junior developers. Core stack: React, JavaScript/TypeScript, Redux/Context API. London-based with hybrid/remote flexibility; salary up to 90k plus potential equity.

up to 90K £

Senior Python Developer - Cyber Security

UKSenior

A Senior Python Developer / Backend Software Engineer builds backend systems at a cybersecurity company in London that uses AI to defend clients worldwide from advanced cyber threats. Day to day: Python backend development on complex systems, with hybrid/WFH options and a salary up to £85,000.

AI Cybersecurity Python

up to 85K £

Senior C#/.NET API Engineer — Full-Stack, Remote/WFH

RemoteUKSenior

API Api Design AWS C# SQL +1 skills

Client Server Limited is seeking a senior C# Developer to own features end-to-end across API design, backend services and front-end delivery. You'll work on a global payments platform in the Corporate Payments…

London Backend Engineer (C#/.NET) - Sports Trading, Onsite + Bonus

Backend Engineer (C#/.NET) joining a sports trading team onsite in London, building robust backend systems, APIs and data flows for high-availability trading. Core stack: C#/.NET, ASP.NET, and SQL or Oracle.

API C# .NET Oracle SQL

Founding Software Engineer Python - Start-Up

RemoteUK

Agentic AI AI API Azure CI/CD +10 skills

Founding full-stack engineer at an early-stage AI start-up building compliance and operational-efficiency technology for the NHS and other regulated industries. You own Python/TypeScript development end to end — architecture, FastAPI backend services, React frontend, and Azure CI/CD — working hybrid from London and Cambridge.

up to 115K £

Backend Software Engineer Python R&D

Backend Software Engineer (Python, R&D) for a cybersecurity technology company that uses AI to protect clients globally from advanced cyber threats. The role involves problem solving on complex backend systems and pays up to £85k, based in London/Cambridge with work-from-home flexibility.

AI Cybersecurity

up to 85K £

Software Engineer Python Genai Llm - Finance

HybridUKContract

Agentic AI API Claude Code Data Engineering Developer Experience +7 skills

A senior Python engineer joins the Investment Technology Research team of a global asset manager in London to prototype, evaluate and build internal GenAI tools - spanning RAG/retrieval workflows, MCP and tool integrations, and LLM model evaluation. 12-month fixed-term contract, hybrid (3 days/week in the London office), salary to £180k.

up to 180K £

Technical Product Manager - Platform Engineering

A hands-on Technical Product Manager role on a global Platform Team at a fintech, focused on SaaS platform engineering. Day to day you'd drive product decisions for the platform, working flexibly from Reigate or home, earning up to £100,000.

up to 100K £