Client Server

Backend Software Engineer Python R&D

UK

Backend Software Engineer / Developer London / WFH to £85k Are you a backend focused technologist who enjoys problem solving and working on complex systems at the cutting edge of technology? You could be progressing…

AI Cybersecurity

Founding Software Engineer Python - Start-up

UK

Agentic AI AI API Azure CI/CD +10 skills

Overview In this Founding Software Engineer role you will shape both technology and product in a fast-growing AI startup. You’ll own the design and development of cloud-native applications, spanning backend, frontend,…

Founding Software Engineer (Python) - AI for Compliance

HybridUK

AI Azure CI/CD Cloud Cloud Native +2 skills

Client Server is seeking a Founding Software Engineer (Python) in the UK to help shape core technology and product in a fast-growing AI startup. You will own the design and build of cloud-native applications, spanning…

Backend Software Engineer Python LLM

RemoteUKFull-time

Agentic AI AI AWS Conversational AI Infrastructure as Code +4 skills

Backend Software Engineer / Developer (Python LLM) Remote UK to £90k Are you a backend focussed Software Engineer looking for an opportunity to progress your career, whilst working remotely on a modern tech stack? You…

Backend Software Engineer Python LLM

RemoteUK

AI AWS Cloud Conversational AI Infrastructure as Code +4 skills

Overview In this remote-first Backend Software Engineer role, you will build and maintain production-grade AI systems and the supporting infrastructure. You’ll own technical decisions, contribute to the evolution of a…

Lead Full Stack Engineer TypeScript Python API

HybridUKLead

Agentic AI AI Analytics API AWS +5 skills

Lead Full Stack Engineer at a profitable London private equity firm, working at the intersection of tech, data, strategy and investment — leading data diligence and shaping tech/data strategy for portfolio companies. Day to day spans TypeScript and Python development, cloud data platforms (AWS/Azure/GCP) and agentic AI, hybrid with three days a week in the London office.

100K – 125K £

Senior Java Backend Engineer — AI-Assisted RealTime Trading

UKSenior

Senior Java backend engineer modernising a high-performance real-time trading system onsite in Newcastle upon Tyne. Day to day: hands-on backend Java development, architectural input on latency-sensitive design, and collaboration with Front Office and engineering teams, using AI tools like Claude to speed up delivery.

AI Java

Java Developer AI Claude - FinTech

UKFull-time

Senior hands-on Java backend developer at a scaling FinTech in Central Newcastle, modernising a C++ trading system into a scalable, low-latency Java application while using AI tools like Claude. Full-time onsite Monday to Friday, collaborating closely with Front Office trading teams.

Software Engineer Python AI - Renewable Energy

UK

Software engineer role building Python-based AI solutions for business systems at a rapidly scaling UK renewable energy company with a growing portfolio of wind and solar assets, taking solutions from build into production. London-based with WFH flexibility, paying up to £120k.

Python Software Engineer Conversational AI

Open 16d UK

AI Conversational AI Python

A remote (UK-based) senior, hands-on Python engineer role at a scaling AI software solutions provider. The person builds production-grade conversational AI systems and their supporting infrastructure using a backend-focused Python stack, earning up to £90,000.

up to 90K £

Senior Java Developer Spring Boot TDD

Open 16d UKSenior

Agentic AI AI Design Patterns Java Multithreading +4 skills

A senior hands-on lead building real-time sports betting backend services with Java and Spring Boot, guiding a small team (~80/20 coding vs leadership), championing TDD and CS fundamentals, and driving delivery with Product Owners.

up to 78K £

full stack developer for sports technology

Open 16d UK

AI API React Rust TypeScript

Full-stack developer at a London-based sports technology company working across US sports (NFL, NBA, baseball, hockey) and betting. You'll shape architecture, build products from the ground up with TypeScript and React, own features end to end through production, and advise the team on using AI in development.

up to 120K £

Python Developer

Open 17d UK

AI AWS Azure Cloud C++ +6 skills

A Python backend developer joins an R&D team building a new greenfield product that uses AI to defend against AI-based cyberattacks. Day-to-day involves building complex Python backend systems, rapid prototyping, and working with Rust, TypeScript/C++ and cloud platforms (AWS/Azure/GCP) in a hybrid role based in Cambridge.

65K – 65K £

Full Stack Engineer / Technical Lead B2B SaaS

Open 18d UKLead

AI API Automation Design Patterns iOS +5 skills

Senior hands-on lead role owning the technical strategy and architecture for a real-time infrastructure company's developer ecosystem: designing APIs and SDKs, expanding client libraries, guiding open-source collaboration and mentoring engineers. Core stack is Ruby, TypeScript and React, with openness to AI tooling like Claude and Cursor.

Senior Data Engineer SQL Snowflake - Finance

Open 18d HybridUKSenior

Agentic AI AI C# Dagster Data Engineering +8 skills

Senior hands-on Data Engineer at a global asset manager in London, building and optimising data pipelines and shaping a new Snowflake-based data platform using Python, SQL, Dagster, dbt and C#, while modernising legacy systems and mentoring junior engineers.

up to 130K £

Backend Developer Golang Node Pub / Sub

Open 21d UK

AI Cloud Distributed Systems Event Driven Architecture Kafka +3 skills

Overview As a Backend Developer, you will shape the core messaging platform that powers real-time interactions at scale. You’ll design and build highly scalable distributed systems and low-latency Pub/Sub components…

Senior Full Stack Developer TypeScript React API

Open 21d On-siteUKSenior

AI API React Rust TypeScript

Overview As a Senior Full Stack Engineer in our new UK operation, you will own the architecture and build products from the ground up in a fast-growing sports tech environment. You’ll work hands-on across the stack,…

Python Developer - Problem Solver

Open 22d UK

AI AWS Azure C++ Cybersecurity +5 skills

Backend Python developer role in a cybersecurity firm's R&D team near Cambridge (office twice a week), building a greenfield product that defends against AI-based attacks. Day to day: rapid prototyping, iterative backend development in Python with exposure to Rust and cloud platforms; salary to £65k.

up to 65K £

AI Analytics BigQuery CI/CD Data Engineering +4 skills

Senior Data Engineer - GCP, BigQuery & DBT | Hybrid

Open 22d EuropeSenior

Poland

Senior data engineer owning the GCP data platform (BigQuery, dbt) for analytics, compliance and AI at a regulated financial services firm in Kraków. Day to day: build batch and real-time ingestion/transformation pipelines, ensure data quality, and contribute to CI/CD and data governance within a squad.