25 of 25 Permanent Legacy Code Jobs in the UK

innovative and positively impactpeoples lives. Were looking for a proactive and experienced Android Developer to work across a portfolio of f ully native apps , primarily developed in Kotlin, with legacy Java code being phased out. The technologies run directly on the phone with limited server interactions. Youll have a strong track record of delivering high-quality apps and … challenges. It is envisaged the role will evolve into a leadership position . Responsibilities : Build on exciting new technologies and integration with wearable devices Develop new features, improve existing code work on ambitious projects ranging from low-level algorithms to high-level system design; plus the occasional development of a prototype app Utilise the latest Android SDKs and frameworks … to implement scalable, maintainable and testable architectures Conduct code reviews and champion high-quality code by leveraging unit tests, continuous integration, and code quality tools Youll need: 5+ years of high-level Android development experience A wider software engineering background (8+ years in total) Excellent Kotlin skills and comfortable with other languages e.g. Java A strong numerate More ❯

based applications. The ideal candidate will have deep expertise in Delphi (especially versions like Delphi 7, XE, or later), a strong understanding of object-oriented programming, and experience integrating legacy systems with modern architectures. Key Responsibilities: Design, develop, test, and maintain software applications using Delphi. Analyze legacy Delphi code and recommend enhancements or modernization strategies. Collaborate with … for Delphi-based applications. Migrate and integrate Delphi systems with .NET, web APIs, or other modern platforms as needed. Write and maintain technical documentation for systems and procedures. Conduct code reviews and ensure adherence to coding standards and best practices. Provide mentoring and guidance to junior developers if applicable. Required Skills & Qualifications: Strong hands-on experience with Delphi (Object … OOP, software development life cycle (SDLC) , and version control (e.g., Git). Experience integrating Delphi applications with web services (REST/SOAP) . Ability to understand and work with legacy code . Strong debugging, problem-solving, and analytical skills. Excellent verbal and written communication skills. About Us: Ascendion is a global, leading provider of AI-first software engineering More ❯

a focus on long-term stability and performance. Collaborate with cross-functional teams, including PO, PDEF, QA, DevOps, and product stakeholders, to define, design, and deliver new features. Refactor legacy code and participate in technical debt reduction. Write clean, scalable, and maintainable code with proper documentation. Participate in code reviews and mentor junior developers where applicable. More ❯

a focus on long-term stability and performance. Collaborate with cross-functional teams, including PO, PDEF, QA, DevOps, and product stakeholders, to define, design, and deliver new features. Refactor legacy code and participate in technical debt reduction. Write clean, scalable, and maintainable code with proper documentation. Participate in code reviews and mentor junior developers where applicable. More ❯

a focus on long-term stability and performance. Collaborate with cross-functional teams, including PO, PDEF, QA, DevOps, and product stakeholders, to define, design, and deliver new features. Refactor legacy code and participate in technical debt reduction. Write clean, scalable, and maintainable code with proper documentation. Participate in code reviews and mentor junior developers where applicable. More ❯

and as the role is fully remote we need someone who is good at collaborating remotely and working autonomously. The core language used will be Python. There is some legacy code in C/C++ so some exposure to that would be helpful. Telecoms experience is essential SIP for instance as is deep knowledge of Linux. Given the More ❯

users) to deliver high-quality software: creating test requirements and ensuring sufficient unit test coverage Contributing to all phases of the development lifecycle; writing well-designed, testable, and efficient code Participating in team improvement activities and initiatives to enhance process and product quality Completing necessary project documentation (status, risks, progress, effort) Proactively integrating with our team, maintaining good communication … other teams Mentoring and assisting in the training of new team members Desired Skills & Experience: University Degree in Computer Science or equivalent Proven ability to produce high-quality, maintainable code Strong problem-solving skills and ability to manage legacy code Excellent understanding of OOP principles and design patterns of software development Minimum 5 years of experience in More ❯

and Verification of complex hardware and software test systems. Development of Suppoting Documentation and Validation Evidence. Fault Finding and RCA of issues identified with the developed Test Equipment. Enhancing Legacy code bases with new features. Rapid Protoyping of New Features and Interfaces as per project needs. Qualifications Bachelor's or Master's degree in Computer Science, Software Engineering … Proficient in SysML and UML, and experience in applying model-based approaches to both systems and software engineering challenges. Experience in developing, maintaining and enhancing complex embedded systems, including legacy codebases. An understanding of the full software development lifecycle, combined with expertise in implementation of precise and traceable software amendments. Experience Experience working in the UK Defence industry or More ❯

used globally in critical healthcare diagnostics and treatment. What You’ll Do Lead architecture, design & delivery across two .NET/C# teams Mentor developers and drive process improvements Modernise legacy code and shape long-term technical strategy Collaborate with Sales, QA & end users, with occasional customer site visits What We’re Looking For 5+ years experience with C# More ❯

used globally in critical healthcare diagnostics and treatment. What You’ll Do Lead architecture, design & delivery across two .NET/C# teams Mentor developers and drive process improvements Modernise legacy code and shape long-term technical strategy Collaborate with Sales, QA & end users, with occasional customer site visits What We’re Looking For 5+ years experience with C# More ❯

HUNDREDS of clients globally (and I'm talking about big house-hold names) alongside millions of users! They built the platform from scratch several years ago using absolutely no legacy code and only the very best technology stack and enterprise tools within a true Microservices environment. Data is absolutely at the heart of what they do and with More ❯

Developer you will be responsible for: Building, developing and maintaining C# applications, tools, and APIs to support internal systems and customer-facing platforms. Working with senior developers to understand legacy codebases and to support long-term migration to modern platforms. Participating in the full software development lifecycle (design, development, testing, deployment, and maintenance). Writing clean, maintainable, and well More ❯

and performance optimisation in AWS environments. Strong understanding of database monitoring, profiling, and troubleshooting tools. Hands-on experience with database migrations and upgrades at scale. Comfortable working with large, legacy codebases and finding pragmatic solutions. Collaborative communicator able to work closely with engineers, product managers, and cloud ops teams. Able to deliver measurable performance improvements in a short timeframe. More ❯

live PnL attribution and feedback to researchers & traders. Hire and mentor the team that will scale this from “clever prototype” to “firm‐wide PnL driver”. Green‐field. No legacy code. You set the standards. The Opportunity All the levers, none of the red tape – direct line to the head of the HFT business, a chance to own the More ❯

live PnL attribution and feedback to researchers & traders. Hire and mentor the team that will scale this from “clever prototype” to “firm‐wide PnL driver”. Green‐field. No legacy code. You set the standards. The Opportunity All the levers, none of the red tape – direct line to the head of the HFT business, a chance to own the More ❯

Senior Plasma Code Developer Abingdon Rd, Culham, UK Full-time Salary: £56,596 (inclusive of Specialist Allowance) + excellent benefits including outstanding pension Division: Plasma Science and Fusion Operations Site Location: UKAEA Culham, Oxfordshire Confirmed Grade: Level 5 Department: Plasma Physics Compensation: GBP 56,596 - GBP 56,596 yearly Company Description By 2050, the planet could be using twice … source data. The Role Are you looking for an exciting opportunity to make a difference? Join our team and contribute to the future of fusion energy. As Senior Plasma Code Developer,you will be responsible for developing and maintaining plasma core and edge modelling codes and ensuring that UKAEA's plasma modelling capability incorporates state-of-the-art physics … models and features needed to reliably model fusion experiments and concept devices such as MAST-U, JET, STEP, and ITER. Code development will be predominantly focused on the integrated transport modelling suite JINTRAC, including the core transport code JETTO, a multi-fluid code to describe the edge plasma (e.g. EDGE2D or SOLPS), and a kinetic Monte Carlo More ❯

Senior Plasma Code Developer Abingdon Rd, Culham, UK Full-time Salary: £56,596 (inclusive of Specialist Allowance) + excellent benefits including outstanding pension Division: Plasma Science and Fusion Operations Site Location: UKAEA Culham, Oxfordshire Confirmed Grade: Level 5 Department: Plasma Physics Compensation: GBP 56,596 - GBP 56,596 yearly Company Description By 2050, the planet could be using twice … source data. The Role Are you looking for an exciting opportunity to make a difference? Join our team and contribute to the future of fusion energy. As Senior Plasma Code Developer,you will be responsible for developing and maintaining plasma core and edge modelling codes and ensuring that UKAEA's plasma modelling capability incorporates state-of-the-art physics … models and features needed to reliably model fusion experiments and concept devices such as MAST-U, JET, STEP, and ITER. Code development will be predominantly focused on the integrated transport modelling suite JINTRAC, including the core transport code JETTO, a multi-fluid code to describe the edge plasma (e.g. EDGE2D or SOLPS), and a kinetic Monte Carlo More ❯

Senior Plasma Code Developer Abingdon Rd, Culham, UK Full-time Salary: £56,596 (inclusive of Specialist Allowance) + excellent benefits including outstanding pension Division: Plasma Science and Fusion Operations Site Location: UKAEA Culham, Oxfordshire Confirmed Grade: Level 5 Department: Plasma Physics Compensation: GBP 56,596 - GBP 56,596 yearly Company Description By 2050, the planet could be using twice … source data. The Role Are you looking for an exciting opportunity to make a difference? Join our team and contribute to the future of fusion energy. As Senior Plasma Code Developer,you will be responsible for developing and maintaining plasma core and edge modelling codes and ensuring that UKAEA's plasma modelling capability incorporates state-of-the-art physics … models and features needed to reliably model fusion experiments and concept devices such as MAST-U, JET, STEP, and ITER. Code development will be predominantly focused on the integrated transport modelling suite JINTRAC, including the core transport code JETTO, a multi-fluid code to describe the edge plasma (e.g. EDGE2D or SOLPS), and a kinetic Monte Carlo More ❯

and SQL Server Enhancing user experiences with modern JavaScript/TypeScript frameworks Driving product improvements through close collaboration with Product Managers, Designers, and other Engineers Ensuring software quality through code reviews, unit testing, and best development practices Contributing to architectural decisions and mentoring junior developers Supporting DevOps processes and cloud-based deployments (bonus if familiar with Azure) Nice to … Have: Experience with PHP and legacy codebases Previous work in the financial services or SaaS industry What We’re Looking For: Proven experience as a Senior or Lead Developer working with C#/.NET Solid knowledge of SQL Server and performance optimization Proficiency in JavaScript/TypeScript and front-end development Strong problem-solving skills and the ability to More ❯

of a cross-functional, agile team, you will shape the frontend roadmap, champion best practices, and foster a culture of engineering excellence. You'll lead the migration from a legacy monolith to a modern microfrontend and Backend-for-Frontend (BFF) ecosystem, leveraging React, Next.js, TypeScript, and advanced communication protocols such as GraphQL and gRPC. What You'll Own Lead … Backend teams to translate complex requirements into elegant, user-centric digital experiences. Advocate for CI/CD best practices, ensuring rapid and safe delivery of features with automated testing, code reviews, and observability. Influence technical strategy, tooling, and processes to continually raise the engineering bar and accelerate delivery velocity. Lead efforts in evaluating and integrating AI tools and automation … innovation. About You Extensive commercial experience building complex frontend applications with React and Next.js, with strong proficiency in TypeScript. Proven track record of architecting scalable frontend systems and migrating legacy codebases to modern frameworks. Deep understanding of accessibility standards (WCAG) and a passion for building inclusive user experiences. Experience working with GraphQL and gRPC APIs in production environments. Exceptional More ❯

of a cross-functional, agile team, you will shape the frontend roadmap, champion best practices, and foster a culture of engineering excellence. You'll lead the migration from a legacy monolith to a modern microfrontend and Backend-for-Frontend (BFF) ecosystem, leveraging React, Next.js, TypeScript, and advanced communication protocols such as GraphQL and gRPC. What You'll Own Lead … Backend teams to translate complex requirements into elegant, user-centric digital experiences. Advocate for CI/CD best practices, ensuring rapid and safe delivery of features with automated testing, code reviews, and observability. Influence technical strategy, tooling, and processes to continually raise the engineering bar and accelerate delivery velocity. Lead efforts in evaluating and integrating AI tools and automation … innovation. About You Extensive commercial experience building complex frontend applications with React and Next.js, with strong proficiency in TypeScript. Proven track record of architecting scalable frontend systems and migrating legacy codebases to modern frameworks. Deep understanding of accessibility standards (WCAG) and a passion for building inclusive user experiences. Experience working with GraphQL and gRPC APIs in production environments. Exceptional More ❯

forefront of digital innovation. About the Company We're a global leader in our sector, trusted by millions worldwide. As part of our ambitious technology transformation, we’re rearchitecting legacy platforms while launching bold new greenfield projects that leverage AI to drive intelligent products and services. This is more than a software engineering role — it's a chance to … be part of a journey that shapes the future of AI in a real-world, high-impact environment. What You’ll Work On Re-architecting legacy systems into scalable, modern cloud-based solutions (Using GCP) Building greenfield applications from the ground up with a strong AI-first mindset Collaborating with data scientists, ML engineers, and product teams to deliver … systems About You Strong experience with C#, Java, or Go A genuine interest in AI/ML (previous experience is a bonus, but not required) Comfortable navigating and improving legacy codebases Eager to work on greenfield projects and adopt new tech Familiar with cloud platforms ( AWS, Azure, or GCP preferred ) Passionate about learning, experimenting, and pushing boundaries Why Join More ❯

built ERP system. Liaise with key internal teams to understand business needs and translate them into robust software solutions. Provide end-user training and technical support. Maintain and improve legacy applications to ensure consistent performance. Write and maintain technical documentation, user manuals, and test cases. Perform thorough testing to identify and resolve software bugs. Skills & Experience: Strong commercial experience … with VB.NET development. Proven ability to maintain and document legacy code. Proficient in Microsoft SQL Server and relational database design. Experience with SAP Crystal Reports. Familiarity with Infragistics Ultimate UI for Windows is a plus. Excellent debugging, troubleshooting, and problem-solving skills Clear communication skills with the ability to liaise across technical and non-technical teams. Knowledge of Software More ❯

built ERP system. Liaise with key internal teams to understand business needs and translate them into robust software solutions. Provide end-user training and technical support. Maintain and improve legacy applications to ensure consistent performance. Write and maintain technical documentation, user manuals, and test cases. Perform thorough testing to identify and resolve software bugs. Skills & Experience: Strong commercial experience … with VB.NET development. Proven ability to maintain and document legacy code. Proficient in Microsoft SQL Server and relational database design. Experience with SAP Crystal Reports. Familiarity with Infragistics Ultimate UI for Windows is a plus. Excellent debugging, troubleshooting, and problem-solving skills Clear communication skills with the ability to liaise across technical and non-technical teams. Knowledge of Software More ❯

built ERP system. Liaise with key internal teams to understand business needs and translate them into robust software solutions. Provide end-user training and technical support. Maintain and improve legacy applications to ensure consistent performance. Write and maintain technical documentation, user manuals, and test cases. Perform thorough testing to identify and resolve software bugs. Skills & Experience: Strong commercial experience … with VB.NET development. Proven ability to maintain and document legacy code. Proficient in Microsoft SQL Server and relational database design. Experience with SAP Crystal Reports. Familiarity with Infragistics Ultimate UI for Windows is a plus. Excellent debugging, troubleshooting, and problem-solving skills Clear communication skills with the ability to liaise across technical and non-technical teams. Knowledge of Software More ❯