Senior Developer role working with C#, .NET 4 & 6, SQL Server, Azure cloud services, SignalR, RabbitMQ, Kafka, Azure Service Bus, and CI/CD via Azure DevOps in an Agile environment. The team delivers a complex SaaS product for a regulated financial marketplace, requiring experience in financial or trading software.

Develop C# .NET BI applications using Visual C#.NET, Oracle, and SQL Server. Support existing applications and environments for a Japanese banking group's BI IT department, including data analysis with T-SQL and PL/SQL. Troubleshoot systems on Windows Servers and databases, liaising with teams in London and New York.

You will work with .NET and C# as a Senior Developer in a Commodities trading environment. The role involves building on experience with the full trade life-cycle for a successful Commodities Trading company.

Citi★3.9 (21k)· London

You will work with Java, Spring, Web3J/Web3JS, Solidity, Docker, and Hardhat/Foundry to build Citi’s Integrated Digital Assets Platform (CIDAP), integrating blockchain networks and digital asset infrastructure.

Citi★3.9 (21k)· London

Work with Solidity, Web3J/Web3JS/Ethers.js/Viem, Java/Spring, Node.js, and blockchains such as Ethereum, Hyperledger Besu, Canton, and Solana, using Hardhat/Foundry/Truffle for testing. Contribute to Citi's Integrated Digital Assets Platform (CIDAP) building Web3 components for tokenization, smart contracts, and on-chain settlement.

Zoopla★3.9 (18)· London

A 12-month maternity cover role on a dual-stack C#, .NET, and TypeScript backend with React microfrontends, using AWS managed services (ECS/Fargate, Lambda, SQS, DynamoDB, DocumentDB) and Terraform/SST. You'll build B2B SaaS software for estate agents and home builders at Alto Software Group. Take end-to-end ownership of features from design to production, working with the product team and AI coding agents.

DeepL★3.8 (4)· London

You'll work with C# / .NET, RESTful APIs, distributed architectures, and optionally React/TypeScript, plus MCP, CLIs, OAuth, and AI coding tools. You join the API Enterprise team, which builds enterprise adoption features (usage insights, cost controls, RBAC, compliance, data residency) for DeepL's Language AI API platform.

You'll work primarily with TypeScript, Node.js, and PostgreSQL on GCP, designing and building scalable backend systems. The team develops and maintains a robust investment platform that powers features like mutual funds, bonds, and family investment tools.

Elsevier★3.8 (769)· London

Work with Java/J2EE, JavaScript, JSP, C/C++, HTML, XML, SQL, Windows, UNIX, .Net, and various data storage subsystems. You'll develop complex software solutions supporting educational electronic health record products that prepare students for digital charting in clinical environments.

RELX Group★3.8 (133)· London

You will work with Java/J2EE, JavaScript, JSP, C/C++, HTML, XML, SQL, Windows, UNIX, and .Net. The team supports products for education electronic health records that introduce students to digital charting and prepare them for clinical documentation.

DeepL★3.8 (4)· London

Work with Kubernetes, Terraform, ArgoCD, Go or Python, and AWS across hybrid on-prem and cloud infrastructure. The Hybrid Platform Engineering track builds and operates the compute layer—Kubernetes control plane, networking, storage, and core services—powering DeepL's language AI products and research. The role involves deepening the hybrid model and unifying workloads across on-prem and AWS.

Checkout.com★3.8 (15)· London

Senior Engineering Manager leading the Disputes team, which builds tools, services, and machine learning models to help merchants manage and win chargeback disputes at scale. The team owns a full stack centered on .NET / C#, React and TypeScript front ends, Python-based ML, and event-driven microservice architectures.

Salesforce★4.2 (1.5k)· London

Success Architect works with Agentforce, Data Cloud, Salesforce Clouds, and data platforms like Snowflake, Databricks, AWS. They drive customer success by optimizing technical architecture for data unification and AI-driven automation, enabling personalized engagement and real-time decision-making.

Principal C#/.NET engineer leading solution design and hands-on development using C#, .NET Core, MongoDB, SQL Server, Kafka/ActiveMQ, and OpenShift/Kubernetes. Mentors developers and directs engineering, applying SOLID, microservices, and contract-first API design within a regulated financial services environment.

Work with C# on .Net Framework 4.5.2+ and .Net 5+, using NUnit, xUnit, REST, Kafka/RabbitMQ, Git, and Linux. You will build Citi’s next-generation Equities technology platform for execution, clearing, and margin processes.

Lead DevOps Engineer: work with AWS, Azure, GCP, Terraform, Linux/Unix, Python/Go/PowerShell/Nodejs/C#, and CI/CD tools (Octopus/TeamCity/Jenkins/Azure DevOps). Role is at a tech consultancy building and running cloud infrastructure, automating deployments with IaC, and managing a team of engineers.

You will develop, maintain, and enhance Excel-based applications and add-ins using C#, .NET, Excel-DNA, VBA, SQL, and potentially Python. Working within a technology solutions team, you will support front-office investment teams (trading, research, portfolio management) by building tools that improve workflow automation, data access, and analytical capabilities.

You'll develop systematic HFT and market-making strategies in cryptocurrency markets using Python for research, signal generation, backtesting, and live performance analysis. Working with your own firm's capital, you'll own the full research lifecycle—from hypothesis to production deployment—optimising execution quality, latency, inventory risk and spread capture across global exchanges.

You'll work with C# and .NET as core systems, plus Python across quant and data groups, and may use other OO languages. The role involves designing and building high-impact trading and research platforms for a fixed-income hedge fund's front-office engineering team.

You will work with C# / .NET, modern front-end frameworks (Blazor, React, Angular, or Vue), and cloud platforms (AWS, Azure, or GCP) on the Web team. This team builds web frameworks powering TradingHub’s MAST and CaaS trade surveillance products for financial institutions.

Work with Kotlin, Java, Spring Boot, microservices, REST APIs, Node.js, TypeScript, Express.js, Nunjucks, AWS/Azure/GCP, Docker, Kubernetes, Terraform, and CI/CD tools. You'll build secure, scalable digital services on large-scale transformation programmes for the Public Sector and Healthcare within Agile, multidisciplinary teams. Mentoring other engineers is expected.

Full Stack Developer role at a specialist investment business. You'll use TypeScript, JavaScript, Python, React, Next.js, Node.js, RESTful APIs, relational/NoSQL databases, Azure, Git, and CI/CD to build and evolve the technology platform with the existing team and senior stakeholders.

Capital on Tap★3.9 (55)· London

First and foremost a software engineering role, you will work with C#, .NET, agentic systems and orchestration layers, and AI enablement tooling. You will build "AI on Tap", the company's internal hub for AI agents, and integrate agentic testing/verification across the pipeline to accelerate delivery for this financial platform.

You'll work across the full stack—backend distributed systems, cloud with IaC, and data pipelines including vector stores—using tools like Claude Code and AI agents for code review, refactoring, and parallel work. This Principal Engineer role on a large iGaming engagement oversees sportsbook, casino, and gaming platforms for a major client, managing a group of engineers and Tech Leads as the named delivery owner. The team includes engineers and Tech Leads that you directly line manage.

EXL Service★3.7 (2k)· London

Design AI architectures on Azure using .NET, React, LLMs, RAG, OCR, and agentic frameworks (LangGraph, AutoGen, CrewAI) to build production-grade GenAI platforms. The role focuses on processing complex insurance documents for underwriting, claims, and reinsurance use cases. You will lead and mentor a team of .NET, React, and GenAI developers.