22 of 22 Legacy Code Jobs in London

designs, and the development team, who deliver them. You will turn HLDs into well‐documented, implementable designs (Low-Level Design) and make sure the code that results is consistent, secure and maintainable. About Bestway Bestway Group is a diversified multinational family owned business with annualised turnover in excess … communities through its operations across the UK, Pakistan and the Middle East Responsibilities Application & low-level design: Own component-level (C4 Level 3) and code-level (C4 Level 4) design and LLDs for our applications. Translate Solution Architects’ HLDs into clear implementation designs, and make sure the team understands ...

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 ...

development team to maintain and update the bespoke ecommerce platform, taking a proactive approach in evolving the back-end technology stack and migrating legacy code across to an ASP.NET framework. Advocate integration of technologies and development methodologies to help drive the business forward and ensure a robust, scalable … Manager to maintain and update the bespoke Classic ASP ecommerce platform. Develop new features for a localized ASP.NET MVC 5 platform and contribute migrating legacy features over to this new platform. Write maintainable, scalable, fault-tolerant code, utilizing SOLID principles and OO design/architectural patterns, TDD, etc. ...

background. Data and applied AI experience help, but we don't screen on them. Must have Proven design and architecture of application modernisation: moving legacy or monolithic systems to modern architectures in increments while the business keeps running A strong application development background, with hands-on credibility … native delivery experience on at least one of Azure, AWS or GCP Engineering discipline: automated testing, CI/CD and safe, incremental change to legacy code Around five years or more in a consultancy, agency or embedded client delivery environment Evidence of client-facing work, such as shaping ...

slowing the pace of new development. Demonstrable hands-on experience applying AI to software engineering at team scale with measurable results (e.g. AI-driven code modernisation, test generation for legacy code or agentic development workflows) and an informed point of view on how AI will change both ...

Back Office Change function, focused on modernising a range of FIS-based back and middle office systems. You'll be working hands-on with legacy code, bringing systems up to current standards, while working closely with database and reporting teams and collaborating downstream with Front Office on changes … what, why and how. What You'll Be Doing Modernising and maintaining FIS-based back/middle office systems, working across a varied legacy tech landscape of differing ages and complexity Delivering a mix of small incremental changes (typically 2-week cycles) and larger project work Engaging directly with ...

reliability and responsiveness. Develop and maintain automated unit and integration tests. Contribute to CI/CD pipelines and engineering best practices. Refactor and modernise Legacy code where required. Produce technical documentation and support continuous improvement initiatives. Required Skills & Experience Strong commercial experience developing native iOS applications. Excellent knowledge ...

from ticket refinement through to delivery, review, and release, proactively communicating progress, risks, and blockers Experience raising and reviewing pull requests, engaging constructively in code reviews Comfortable with object-oriented design and writing maintainable, testable PHP code Experience working on production systems where reliability, security, and user impact … critical Ability to work confidently with legacy code and improve it incrementally, making pragmatic trade-offs where appropriate Minimum of 2-3 years of commercial PHP experience, including work with a modern framework such as Laravel or Symfony Experience building and consuming RESTful APIs and integrating with third ...

encouraged to help others grow - you will pass on your expertise to other developers, whilst continuing to grow yourself. Sometimes deciding what code to write is as hard as writing the code itself. As an engineer you'll be involved in product decisions as well as technical ones. … more of modern Android development tools, including Jetpack Compose, Coroutines/Flow, MVVM, Webviews, other Jetpack libraries, and modular app architectures. You test your code and promote a culture of testing. Demonstrate experience with some of JVM unit testing, instrumented testing, and UI regression testing You are comfortable working ...

medium-sized applications that business people use in their day-to-day work. What you will do in this role Primarily work on legacy code, and sometimes work on green-field development. Lead small projects to completion. Hands on with business users, sometimes collaborating with them to improve … Strong verbal and written communication skills. Fluency in one or both of Python and C#. Ability to work with AI coding assistants (e.g. Claude Code) to accelerate software development. Bachelor's degree in Computer Science or Software Engineering (or equivalent). 6+ years of Software Engineering experience. For more ...

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 ...

London is seeking a Software Engineer for the Unified Platform - Business Experience team. You will maintain legacy code and contribute to green-field development to empower business users with DRW technology. The role requires 6+ years of software engineering, fluency in Python and/or C# ...

across design, build and deliver greenfield services, whilst mentoring a small team as they cross-train into Java. You will lead the shift from Legacy code to modern JVM technologies, establish reference architectures, and mentor a transitioning engineering team. The Tech Stack & Methodology includes - Modern Java (Java ...

team in London. You will build high-quality front-end features with React and TypeScript, focusing on clarity, performance, and maintainability. You will refactor legacy code, fix issues across the stack, collaborate with product managers and designers, and provide code reviews while mentoring teammates to improve quality ...

seeking a Software Engineer for the Unified Platform - Business Experience team in London. You will contribute to legacy code, take ownership of small projects and collaborate with business users to improve tooling. Fluency in Python or C#, strong communication, and 6+ years in software engineering are required; Bachelor ...

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 ...

high-performance C++ systems powering price discovery and analytics across asset classes in a London-based team. You will work with senior engineers, transitioning legacy code and delivering features to production, while engaging with quants and brokers to understand needs. The role aligns with a growth mindset ...

observability Improve platform reliability - implement monitoring, alerting, and performance optimizations for production AI systems Mentor and uplift junior and mid-level engineers through code reviews, pairing, and technical guidance Shape engineering practices - contribute to architecture decisions, coding standards, and team processes Collaborate cross-functionally with Product, Design, Compliance … applications with good state management, performance, and testing Strong Python backend experience - FastAPI, Django, or Flask with async programming, clean architecture, and production-grade code System design skills - you can design scalable, maintainable systems and articulate trade-offs clearly API design expertise - REST, WebSockets/SSE, and understanding ...

role We are looking for a senior unity developer to join our ranks at Metavision Studios to develop, and maintain live-ops of our legacy projects. In doing so, you’d play a core part in our mission to expand and build on the success … Interactive Media portfolio. This is a high impact role, where you’d be accountable for how Metavision Studios steps into the more legacy mobile & console spaces. Sat within our wider UGC team at Metavision, you’d be part of the foundation of mobile expansion working with our Studio ...

hiring Senior Software Engineers to work on business-critical products across our portfolio. You'll be embedded in a product team, working across legacy and greenfield environments, translating ambiguous business problems into production-grade solutions. We care about engineering judgement - the ability to decompose hard problems, design systems that … thinking, not your toolset. You'll work on systems with real users, real constraints, and real consequences. Some of that work will be modernising legacy codebases that have served public services for years. Some will be building new capabilities from scratch. All of it requires someone who thinks ...

getting in early on a medical device project? We're working with a client who needs an experienced Embedded engineer to help bring a Legacy system up to scratch, reporting directly to the technical lead. What you'll be doing: Developing and maintaining Embedded C firmware on STM32 Working … within an ISO 13485/IEC 62304 regulated environment Getting to grips with (and improving) a Legacy codebase Helping shape the project scope and timelines from the start What they're looking for: Strong Embedded C on ARM microcontrollers, ideally STM32 Hands-on experience ...