Client Server

Senior C# .NET Full-Stack Engineer – Remote

HybridUKSenior

Senior full-stack engineer owning features end-to-end (API, backend, frontend) with C# .NET and Vue.js for an international payments platform, including architecture ownership and collaboration with Product, Design and Compliance. Mostly work-from-home with twice-weekly presence in the Bracknell office (hybrid).

API C# .NET Vue

Senior C# .NET API Engineer – Full-Stack, Remote

UKSenior

Senior C# engineer owning features end-to-end: designing scalable .NET APIs and backend services, building Vue.js frontend components, and driving architectural decisions while mentoring others and modernising legacy systems. Remote-friendly, with office presence twice weekly in Bracknell.

API C# .NET Vue

Backend Engineer TypeScript – Remote/WFH Cyber Security

HybridUK

Builds and owns TypeScript backend services for a cybersecurity company's customer portal, taking features from rapid prototype to production-ready systems with a security focus. Hybrid role: two days per week in the Cambridge office, the rest working from home.

TypeScript

Python Backend Engineer – AI Security R&D (Cambridge)

HybridUK

AI Prototyping Python Rust TypeScript

A Python backend engineer joins the R&D team in Cambridge to build a new greenfield product that combats AI-based security threats, delivering complex backend systems through rapid prototyping and iterative development, mainly in Python with exposure to Rust and TypeScript, in a hybrid work arrangement.

Front Office C++ Backend Engineer - London Hybrid to £125k

HybridUKSenior

C++ Design Patterns Linux

Senior C++ backend engineer building a core equity trading system for front-office desks in London. Day-to-day is C++17/20 on Linux tackling low-latency, high-volume data challenges alongside traders. Hybrid role (one day a week from home), paying up to £125k plus bonus.

up to 125K £

Backend Engineer (C#/.NET) - Trading Systems, London

Backend engineer building high-performance trading systems in C#/.NET with SQL for a hedge fund technology team in London, collaborating with quantitative researchers on valuation and pricing components and owning projects from design through delivery.

C# .NET SQL

Backend Engineer (C#/.NET, SQL) – Hedge Fund Systems

Client Server Limited is seeking a Backend Software Engineer in London to design and implement high-performance trading systems using C# and SQL. The role emphasizes ownership from day one, collaboration with quant…

C# SQL

Backend Developer Typescript - Cyber Security

AI Containerization Cybersecurity Kubernetes Python +2 skills

Backend Developer designing and building TypeScript backend services for the customer portal at a leading cyber security technology company in Cambridge (hybrid, 2 days/week in office), protecting organisations from AI-driven cyber threats. Stack includes TypeScript and Kubernetes, with Python/Rust desirable.

up to 70K £

Python Software Engineer Agentic Ai

RemoteUK

Agentic AI Agile AI Ai Enablement API +10 skills

A Python engineer builds backend code and APIs focused on agentic AI — developing, integrating and deploying intelligent agents powered by LLMs like Claude and ChatGPT, with prompt engineering, CI/CD and ideally AWS and Neo4j. London-based with work-from-home one day a week, salary up to £65k plus bonus and EMI share options.

up to 65K £

Backend Software Engineer Python R&D

AI AWS Azure C++ Cybersecurity +5 skills

Backend Software Engineer in an R&D team at a cybersecurity technology business, building a Greenfield product to combat AI-based attacks. Day to day is rapid prototyping and iterative development, mainly in backend Python with some Rust and other emerging technologies; hybrid role based in London (2 office days/week), salary up to £85k plus bonus.

up to 85K £

Senior React Architect – Lead Frontend for Scalable FinTech

UKLead

HireHi is hiring a Lead Front End Engineer in London to architect and build React front-ends for its financial operating system used in live events. The role stays hands-on, covering performance, accessibility, API/payment and real-time integrations, and front-end tooling decisions.

react developer for live events

API JavaScript React Redux TypeScript

Lead/ senior React developer for a startup building a financial operating system for live events (payments, queue reduction). Day to day: own front-end architecture in React/TypeScript, integrate payment APIs and real-time data, mentor juniors. London office 3-4 days/week for first 6 months, then flexible.

Senior Java Developer Spring Boot TDD

UKSenior

A Senior Java Developer / Backend Engineer will guide and inspire a small, high-performing team building real-time sports betting applications at a global games software house. Core technologies are Java, Spring Boot and TDD, with a salary up to £78k and WFH flexibility in Manchester.

Backend Software Engineer Python R&D

AI AWS Azure Cloud C++ +5 skills

Join an R&D team building a greenfield backend product that counters AI-based security threats. The role is primarily Python (with Rust/exposure to other languages), spanning rapid prototyping, architecture, and deploying/scaling on cloud platforms (AWS/Azure/GCP). London-based with WFH.

up to 85K £

Backend Software Engineer C++ Python - Trading

A backend engineer builds and optimizes data-driven systems in C++ and Python that power systematic trading strategies, collaborating with senior engineers and quantitative researchers in a Linux environment at a tech-led trading firm.

Technical Product Manager - Platform Engineering

Technical Product Manager (SaaS Platform Engineering) Reigate / WFH to £100k Are you a tech savvy, senior Product Manager with a software engineering background? You could be progressing your career in a hands-on…

Lead C# Developer .Net - FinTech

HybridUKLead

Hands-on Lead C# Developer role building and leading development of complex, scalable C#/.NET desktop applications for a global fintech. Based in Reigate, Surrey with hybrid working (3 days a week from home), paying up to £100k plus a ~20% bonus.

C# .NET Fintech

up to 100K £

Quantitative Developer Python C++ - MFT

RemoteUK

C++ Java NumPy pandas Python +1 skills

Quantitative Developer (Python C++ MFT) London / WFH to £175k+ Opportunity for a highly talented Quantitative Developer with Python expertise to progress your career in an impactful role at a global trading firm with…

Senior Software Engineer C# Python AI

RemoteUKSenior

Agile AI Angular AWS Azure +14 skills

Salary: £40,000 - 70,000 per year Requirements Strong backend software engineering skills with C# and/or Python Strong knowledge of Computer Science fundamentals, including OOP, multithreading, design patterns, and…