24 of 24 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 ...

Mobile applications that serve tens of millions of cardholders worldwide demand a relentless focus on user experience and code quality. As an iOS Engineer, working in a hybrid mode in London, you will sit at the intersection of scale and creativity, where ambiguity is part of the challenge … work matters because every feature you help shape reaches users around the world. Responsibilities Build and maintain iOS applications and write and delete code as needed Use build tools such as Tuist, xcodebuild, GitHub Actions and Circle CI and apply continuous integration patterns Find and fix bugs and apply ...

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 ...

stack features across .NET 8 services and React front ends Lead large projects from design to rollout with one or two other engineers Modernise legacy code, building in automated tests and observability Partner with product, engineering and client support, and join our on-call rotation Mentor engineers through … code review and pairing, and help us hire WHAT YOU'LL BRING: 4–8 years of professional software development experience Strong C#/.NET backend skills, including in large, established codebases Experience with React, TypeScript and SQL Daily, hands-on use of AI coding assistants A record of delivering ...

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 ...

HAVE Building systems with a constant focus on reliability, scalability, and maintainability. Designing 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. … week Highly competitive compensation plus annual discretionary bonus Working with a team of high‐performing individuals, we all push each other forward Informal dress code and excellent work/life balance A fast‐growing global firm with plenty of opportunities where you will have a significant impact Maven ...

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. ...

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 ...

technology platform. You'll stabilise it, modernise it and lead its migration to AWS.This is a senior engineering role for someone who still writes code every day. You'll work closely with the platform architect, set technical direction, and guide a team of experienced engineers and contractors.The roleInvestigate … reliability, performance and latencyDesign and build new services using modern Java (Java 25) and Spring BootLead the migration of existing applications to AWS, replacing legacy frameworks with cloud-native solutionsSupport the migration of the caching layer to RedisUse AI-assisted development tools (e.g. Amazon Kiro) to analyse legacy ...

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 ...

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# ...

join the Treasury Payments team. You will design and deliver full-stack features across .NET 8 services and React front ends, modernising a large legacy codebase with automated tests and observability. Daily collaboration with product, engineering and client support is expected, including on-call rotation. You will own critical ...

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 … decisions — from system design and architectural choices to setting engineering standards across the team Translate complex business requirements into robust, high‐quality code — working closely with quantitative analysts, traders, and business stakeholders Craft high‐quality, scalable software in an agile environment, leveraging AI‐powered coding tools to accelerate delivery ...

solutions. You will work with cross-functional teams to translate user needs into robust backend services. The role focuses on API development, modernization of legacy code, and strong database design with SQL. UK-based applicants with full right to work are required. #J-18808-Ljbffr ...

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 ...

globally distributed team. You should have a degree or equivalent experience, solid UIKit/MVVM knowledge, REST APIs, and familiarity with Objective-C legacy code. Join a fast-paced, small-team setting with global impact. #J-18808-Ljbffr ...

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 ...

architecture decisions, and mentor engineers across product teams. You will optimize databases, APIs, and processing workflows, participate in incident response, and drive modernisation of legacy code without business disruption. Strong knowledge of PHP 8+, Yii2, PostgreSQL and CI/CD required. #J-18808-Ljbffr ...

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 ...

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 ...

layers, and background processing Identify and resolve production incidents, bottlenecks, and technical risks Participate in architectural decision-making and long-term platform evolution Conduct code reviews and maintain engineering quality standards Mentor developers, support onboarding, and provide technical leadership within the team Collaborate with Product, Growth leads … architecture and system design principles Strong PostgreSQL experience: schema design, indexing, query optimization, performance tuning Experience designing APIs and service integrations Solid Git workflows, code review practices, and CI/CD experience Strong debugging, troubleshooting, and root-cause analysis skills Leadership & Ownership: Proven experience leading major technical initiatives Ability ...

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 ...

Mobile applications that serve tens of millions of cardholders worldwide demand a relentless focus on user experience and code quality. As an iOS Engineer, working in a hybrid mode in London, you will sit at the intersection of scale and creativity, where ambiguity is part of the challenge … modern approaches. The work matters because every feature you help shape reaches users around the world.ResponsibilitiesBuild and maintain iOS applications and write and delete code as neededUse build tools such as Tuist, xcodebuild, GitHub Actions and Circle CI and apply continuous integration patternsFind and fix bugs and apply functional ...