Build features across a dual-stack backend (TypeScript, C#, .NET) and microfrontend React apps, using AWS (ECS, Lambda, SQS, DynamoDB, DocumentDB), Terraform, SST, and AI coding agents. You'll evolve a B2B SaaS platform that powers UK housing transactions, adding new AI capabilities alongside a mature .NET foundation.

Full-stack Java development on Linux/Unix, using AI coding tools like Claude Code, Windsurf, Devin, or GitHub Copilot. The role is for Ascendion, a technology services company.

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 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.

You'll work with frontend (TypeScript, React, Angular, Vue, Next.js, Tailwind), backend (Python, Node.js, Java/Spring, C#/.NET), databases (SQL, NoSQL, vector databases), LLM frameworks, and cloud platforms (Azure, AWS, GCP) including Docker and CI/CD. QuantumBlack, an AI division of McKinsey, builds industry-shaping products and tools across diverse industries by pairing software engineers, AI engineers, and data scientists with client leadership. As a Senior Software Engineer, you'll lead architecture design, mentor teams in engineering excellence and Agile practices, and drive technology decisions on scalable solutions.

Build and maintain the company’s platforms using JavaScript, Node.js, Next.js, Express.js, React/React Native, .Net 4.8/9/10, C#, HTML/CSS, and API Restful Services. You will develop both web and mobile applications, collaborating with the team while working independently.

DeepL★3.8 (4)· London

You will work with React, C#/.NET, and AI-powered tools like GitHub Copilot and Claude, building full-stack Enterprise features. The team, part of DeepL’s Business Acceleration Track, architects the company’s revenue and billing systems, including Identity & Access Management and subscription architectures for global enterprises.

DeepL★3.8 (4)· London

Work with C#/.NET Core, Python, Kubernetes, and React on DeepL’s Language AI platform—building translation, writing, and real-time voice solutions used by over 300 million users globally. You will own revenue-critical systems end-to-end, from architecture to production.

DeepL★3.8 (4)· London

You will work with C#/.NET Core, Python, React, and Kubernetes, plus AI-assisted tools like Copilot and Claude. You’ll ship end‑to‑end user‑facing features for DeepL’s Language AI platform, which provides human‑like translation, improved writing, and real‑time voice translation to millions of users and businesses globally.

A full-stack or backend specialist will use C# and .NET Framework, SQL Server (T-SQL), RESTful APIs, Azure DevOps, and messaging queues (RabbitMQ, Kafka) to build secure integration pipelines and backend services. They will execute a critical integration programme for an international Wealth Management firm to connect core internal and third-party systems.

Senior Java developer working with Spring Boot, J2EE, RESTful APIs, Microservices, Kubernetes or OpenShift, Angular, JavaScript, Bootstrap, HTML5, CSS3, SQL, PL/SQL, JBoss or Oracle 10gAS, Git, Maven, Jenkins. You will design, develop and enhance enterprise BSS/OSS solutions, mentoring junior developers within an Agile team.

You will work with .NET, Java, Python, TypeScript and AI coding tools such as GitHub Copilot, Claude Code or Codex. You will lead a small engineering team driving an AI-first transformation at a growing technology business, shaping engineering strategy and building modern, AI-ready foundations.

You will work with C#, ASP.NET Core, React/Angular/Blazor, REST APIs, Git, Azure/AWS, and CI/CD tools. The role is with 83zero, though the listing does not specify a particular team or product project.

You will work with C#, .NET, SQL, Git, Azure DevOps, Microsoft Azure, and APIs to develop, maintain, and enhance business-critical applications for Hays Technology.

Senior C#/.NET engineer building scalable backend systems, APIs, and data-driven applications for client-facing platforms at a systematic investment firm. Works with stakeholders on architecture and product direction in a centralized post-trade engineering team.

The role involves C#, ASP.NET Core, async/await, Entity Framework Core, Git, and optionally Azure DevOps, Docker, and Playwright. You will build backend services, integration layers, and AI API integrations for large-scale websites, apps, and platforms delivered to global brands.

You will work with C#, .NET Core 8+, Angular, Event-Driven Architecture and Distributed Systems to rebuild business-critical energy trading applications—Settlements, Trade Capture and Trade Operations—as part of a greenfield modernisation moving away from legacy technology.

You will work with C#, .NET Core 8+, Angular, Event-Driven Architecture and Distributed Systems. You will modernise business-critical energy trading applications, including Settlements, Trade Capture and Trade Operations systems, moving from legacy to modern .NET Core.

You will work with .NET as a Full Stack Developer on an NHS digital transformation programme, building and enhancing critical healthcare applications. The team focuses on delivering scalable, secure, cloud-native solutions.

Work with C#, .NET 8+, Blazor, Azure (Service Bus, Container Apps, SQL), Terraform, and CI/CD to build event-driven microservices that integrate AI/LLM components at an AI and PropertyTech scale-up. You'll join a small, close-knit team collaborating directly with

You will work with C# and .NET to develop and enhance applications, including greenfield projects and platform improvements, while collaborating with cross-functional teams. The company is a data-focused organization where engineering quality and technology drive key decisions. You will support junior engineers.

Senior Software Engineer works with C#, SQL, .NET Framework 4.8 (ASP.NET MVC5, WebAPI2, EF6), modern .NET 6+, JavaScript/TypeScript, AWS (Lambda, SQS, SNS, RDS) to modernise core C#/SQL systems by extracting legacy business logic, building clean services, and verifying changes via shadow-mode testing.

Mimecast★3.5 (31)· London

Build and maintain full-stack features using C# (.NET) and Java for backend services, React for user interfaces, and a cloud-native stack including AWS (SQS, S3, Bedrock), PostgreSQL, Elasticsearch, Kubernetes, and Grafana. Join a product engineering squad within the Governance, Compliance & Insights pillar that delivers enterprise-scale compliance and archiving for collaboration and email data from platforms like Slack and Microsoft Teams.

Mimecast★3.5 (31)· London

Build and maintain full-stack features using Java, C# (.NET), React, AWS (SQS, S3, Bedrock), PostgreSQL, Elasticsearch, Kubernetes, and Grafana. You will join a product engineering squad within the Governance, Compliance & Insights pillar, building services that help enterprise customers govern and archive collaboration and email data from platforms like Slack and Microsoft Teams.