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.

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.

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.

Python micro-services with RabbitMQ and OpenShift/Kubernetes, using SQL Server and Parquet. The London Commodities Risk Technology team builds a front-office distributed platform for trading and risk calculations on assets like oil, gas, power, and exotics, collaborating with traders and quants.

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.

You will work with Azure DevOps Pipelines, CI/CD, Atlassian Confluence, Jira, PowerShell, Python, C#, SQL, and cloud deployments to Microsoft Fabric/Synapse/Azure, Snowflake, Power BI, and application security tools. You will help build automation, CI/CD pipelines, and release processes for in-house developed solutions at the Universities Superannuation Scheme pension scheme.

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 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.

Build ultra-low-latency, high-throughput systems using Rust in production, with additional exposure to C#, C++, FPGA, kernel bypass (DPDK, RDMA). The systems power trading across traditional markets and digital assets at firms operating in HFT, crypto exchanges, and DeFi infrastructure.

Meta★4.0 (1.1k)· London

Work with SQL, ETL, data modeling, and languages like Python, C++, C#, or Scala to design scalable data solutions for Meta's family of apps (Facebook, Instagram, Messenger, WhatsApp, Reality Labs, Threads). Collaborate with engineering, data science, and product teams to optimize growth and user experience for billions of users and businesses.

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.

bp★3.8 (5.2k)· London

Work hands-on with Python, SQL, C#, Spark/PySpark, Palantir Foundry, planlogic EOS ETRM, Stonebranch, and AWS to build and maintain backend services, RESTful APIs, front-end components, and data pipelines. You will support bp’s LNG Energy Trading and Risk Management applications, including bespoke solutions for trade capture, operations, analytics, risk, reporting, and finance. This Staff Engineer role also includes mentoring and line management of the engineering team.

You'll work with TypeScript, Node.js, AWS serverless technologies (Lambda, SQS, EventBridge, API Gateway), MongoDB, Terraform, and GitHub Actions. Seccl is an embedded investment platform helping people invest better, owned by Octopus. You'll design and operate services within cross-functional squads, mentor engineers, and support regulated investment operations in a build-and-run model.

You'll develop full-stack software products using TypeScript, React, Python, Node.js, Java/Spring, C#/.NET, SQL, NoSQL, vector databases, LLM frameworks, and cloud platforms (Azure, AWS, GCP) with Docker and CI/CD. QuantumBlack, AI by McKinsey is a multidisciplinary group creating industry-shaping digital products and tools for clients across industries. You'll work hands-on with global technologists, designers, and strategists to build cutting-edge solutions while mentoring client teams on engineering practices and Agile values.

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.

C# .NET, Azure, SQL Server, Kafka, IBM MQ, FIX Protocol, event-driven and microservices architectures. You will define the architecture for enterprise trading platforms, modernising front, middle and back-office systems within a global financial services organisation.

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

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.

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.

Lead engineers use Java, C#/.NET, Python, TypeScript, JavaScript, React, Go, Ruby, Scala, R, and SQL; Git, MacOS/Linux, and CI/CD; and AI-assistive tools. They lead multi-client software consultancy engagements, building and delivering production agentic systems and ML-powered features. The team is typically one to two clients per year.

JPMorgan★3.9 (20k)· London

Lead projects on the Strategic Index Technology team, using Python, Java, C++, or C# to build and maintain the cross-markets index platform alongside Quantitative Research, Trading, and Sales.

NiCE★3.4 (30)· London

You'll work with Python, Go, Java, C#, Bash, PowerShell, AWS (EC2, ECS, Lambda, DynamoDB), CloudFormation, Terraform, Jenkins, GitLab CI/CD, CircleCI, Docker, Kubernetes, Prometheus, Grafana, ELK stack, Cloudwatch, and optionally Grafana Observability Suite, Splunk, Datadog, PagerDuty, Rundeck, Ansible, Puppet, Chef. As an individual contributor, you'll run production, improve reliability, and support multiple large distributed software applications for NiCE, a provider of customer experience, financial crime, and public safety software.

Works with .NET, C#, Azure (Functions, Service Bus, Cosmos DB), SQL Server, and explores AI concepts (LLMs, prompt engineering). The engineering team builds publishing systems for content delivery, access control, workflow, analytics, and eCommerce at Sage, an academic publisher. The leadership role shapes technical direction and mentors colleagues.

Microsoft★4.2 (9k)· London

This role involves coding in C, C++, C#, Java, JavaScript, or Python, applying AI, LLM tooling, and CI/CD practices. Engineers join a cross-functional team of software engineers, data scientists, and designers to build production-ready, AI-powered solutions for strategic customers, owning end-to-end system design for cloud and AI workloads.