18 of 18 Legacy Code Jobs in London

large-scale, business-critical application, you'll play a key role in modernising and simplifying a complex Python estate. The work will involve refactoring legacy code, breaking down monolithic applications into modular components, and supporting the migration of solutions from on-prem environments into AWS. This … Stack Engineer. Expert-level Python development skills with strong Object-Oriented Programming (OOP) experience. Proven experience developing, maintaining and modernising large enterprise applications, including legacy code refactoring. Strong experience with AWS, cloud migration projects, and modern software engineering practices. Strong SQL skills, with experience working on data-intensive ...

operations – a mature, revenue-generating system that has evolved over years and continues to scale. If you enjoy owning real systems, thinking architecturally, improving legacy code thoughtfully rather than rewriting it, and being trusted to deliver without heavy supervision, this role will feel unusually well-matched. The role … calm, root‐cause mindset Incrementally improving system architecture using sound design principles (including modular design, DDD‐style thinking, and pragmatic architectural patterns) Reviewing code, raising standards constructively, and contributing to a disciplined engineering culture Leveraging modern tooling (including AI‐assisted development) to improve quality and velocity This ...

untangling complex systems and modernising core infrastructure without breaking production. This is an exciting opportunity to modernise core C#/SQL systems! Extract legacy business logic, build clean services, and verify changes in shadow mode with zero downtime to revenue flows. Extract business rules scattered across C#, embedded JavaScript … rules assemblies. Build new services cleanly. with proper Dependency Injection (DI), robust authentication/authorization, structured logging, and full observability. Work fluently across both legacy .NET Framework 4.8 (ASP.NET MVC5, WebAPI 2, EF6) and modern .NET, as both will coexist for the whole transition period. Navigate across the multiple ...

pair programming, mob programming, and test‐first development practices Build and maintain CI/CD pipelines and deploy services to cloud environments Continuously refactor code and uphold high standards of code quality and reliability Participate in architectural and technical design discussions Collaborate closely with front‐office stakeholders … experience with event‐driven systems (event streaming and/or event sourcing) Experience with CI/CD tools and practices Strong background in refactoring legacy code and maintaining clean, maintainable systems Experience working in Agile/XP environments, ideally including mob programming Excellent communication skills with the ability ...

Building systems with a constant focus on testing, reliability, scalability, and maintainability.Designing, modeling, and programming in a variety of languages and technologies. Working on legacy code as well as green field development.Initiative driving projects to completion.Learning and promoting new technologies with a focus on best practices.Providing on-call ...

time messaging systems. Enhance Observability: Build deep telemetry and metrics to diagnose latency and performance anomalies across the full client-to-backend path. Kill Legacy Code: Gracefully sunset legacy networking components without interrupting the user experience for hundreds of millions of clients. Who You Are An Expert ...

systems with a constant focus on testing, reliability, scalability, and maintainability. Designing, modeling, and programming in a variety of languages and technologies. Working on legacy code as well as green field development. Initiative driving projects to completion. Learning and promoting new technologies with a focus on best practices. ...

environment that values innovation, teamwork, and shared success. You love to build new things but also don’t shy away from digging into a legacy codebase. You love to work in a complex problem domain that is implemented with simple software systems You have an interest or experience ...

work today.You'll have hands-on access to Citi's internal GenAI ecosystem: from GitHub Copilot and Devin.AI for agentic code generation, to Citi Squad for automated code reviews, to Stylus Workspaces — Citi's in-house GenAI platform powered by top-tier LLMs including Gemini, OpenAI, Claude, Llama … direction and key decisions — from system design and architectural choices to setting engineering standards across the teamTranslate complex business requirements into robust, high-quality code — working closely with quantitative analysts, traders, and business stakeholdersCraft high-quality, scalable software in an agile environment, leveraging AI-powered coding tools to accelerate ...

team is building systems that detect infringement, streamline R&D, and empower creators to move faster. It’s a true greenfield opportunity, no legacy code, no bureaucracy, just the freedom to solve challenging technical problems with impact. The founding team comes from some of the world’s most ...

lean heavily into AI‐driven development. Using Goldman Sachs' AI tooling and agentic coding assistants, you will govern multiple AI agents, rapidly comprehend large legacy codebases, generate and assess production‐quality code, and accelerate every phase of the software development lifecycle. Your Impact Drive a strategic transformation : Work … centric, AI‐driven world, and define and deliver the requirements for CTL integration. Multiply your output with AI : Orchestrate AI coding agents (e.g., Claude Code, GitHub Copilot, Devin, Gemini Code Assist) across all stages of the SDLC while maintaining mastery, quality, and production fitness over all AI‐generated ...

lean heavily into AI‐driven development. Using Goldman Sachs' AI tooling and agentic coding assistants, you will govern multiple AI agents, rapidly comprehend large legacy codebases, generate and assess production‐quality code, and accelerate every phase of the software development lifecycle. Your Impact Drive a strategic transformation : Work … centric, AI‐driven world, and define and deliver the requirements for CTL integration. Multiply your output with AI : Orchestrate AI coding agents (e.g., Claude Code, GitHub Copilot, Devin, Gemini Code Assist) across all stages of the SDLC while maintaining mastery, quality, and production fitness over all AI‐generated ...

including trading systems, exchange connectivity solutions, and monitoring systemsWorking in multiple languages, including C++, and PythonTesting at the unit, functional, and integration levelWorking on legacy code as well as greenfield developmentProviding on-call support as neededCollaborating with traders, researchers, and software engineers within our group as well ...

beyond the team, and drive data-driven decisions. You love to build new things but also don’t shy away from digging into a legacy codebase. Qualifications Experience working with Python & Serverless Strong fundamental programming skills (data structures, algorithms) Excellent communication skills, both written and spoken An interest ...

drive data-driven decisions across talented colleagues. You love to build new things but also don’t shy away from digging into a legacy codebase. You will mentor builders across the company to advance from basic AI usage to sophisticated system creation, aligning with our long-term mission. #J ...

London in need of a developer to architect and enhance their regulatory reporting infrastructure. You'd be designing systems from scratch, not just maintaining legacy code. The technical challenges involve processing massive datasets, implementing robust validation protocols, and creating scalable solutions that meet strict regulatory requirements. ...

high-quality engineering on mature platforms. The ideal candidate will have 8-15 years of experience, strong Python skills, and comfort navigating complex legacy code. This position offers an opportunity to make architectural decisions and contribute to the company's operational growth, while working alongside senior decision-makers. #J ...

more modern Android development tools, including Jetpack Compose, Coroutines/Flow, MVVM, Webviews, other Jetpack libraries, and modular app architectures Ability to test code and promote a culture of testing Experience with JVM unit testing, instrumented testing, and UI regression testing Comfortable working with cutting-edge technologies and legacy code Experience in, or willingness to take on, a leadership role in team projects Rough understanding of iOS development and interest in learning more Nice to have: familiarity with Swift and ObjectiveC for iOS, Scala and Typescript for server-side development Условия: £82,000 Per year One office ...