1 to 25 of 46 Permanent Legacy Code Jobs in the UK

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 ...

closely with chemistry subject-matter experts and implement their algorithms using sound design patterns and modern C++. You'll be one of the main code reviewers, protect the quality and consistency of the architecture, and mentor junior developers as they continue to grow. Key responsibilities Maintain and modernise … legacy C++ codebase, migrating it gradually to modern C++ Implement new cheminformatics algorithms specified by the SMEs Review algorithm specifications for feasibility and clarity before implementation Act as a primary code reviewer, protecting the team's architectural consistency and code quality Own the test strategy for your ...

active, hands-on Software Engineer role that combines core web development execution with dedicated delivery coordination. While primarily an engineering role writing code and addressing backlog requirements, this position carries a specialist focus: directly assisting the Engineering Manager in driving flow, managing Jira Kanban boards, and maintaining strict release … ensure pre-production operational quality, and orchestrate smooth production releases. Key Responsibilities Core Engineering Responsibilities Active Codebase Contribution: Actively write clean, secure, and performant code in PHP and/or Python to deliver work from the backlog, including feature development, bug fixes, and critical technical debt. Full-Lifecycle Ownership ...

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. ...

performance web applications using React, Node.js, and TypeScript. You will own the full lifecycle, from frontend UI components to backend business logic. Infrastructure as Code (IaC): Lead the implementation of cloud environments using Terraform. You will treat infrastructure as a first-class citizen, ensuring all client environments are reproducible … performance tuning. AI-Accelerated Workflow: Proactively utilise AI-assisted development tools (e.g., GitHub Copilot, Cursor, Claude) to accelerate delivery, automate testing, and refactor legacy code, while maintaining strict manual oversight for security and quality. Automation & CI/CD: Build and manage automated pipelines that bridge the gap between ...

between ship and shore), Fastnet (packet transport and bandwidth management) and Deploy (software updates to vessel endpoints) — all C#, .NET and AWS. Beyond writing code, you'll hold pull request authority over other developers' work, own the weekly production release builds across the product estate, and carry the security … cases, and rollback path included. Act as a Change Authority: review and authorize pull requests from other developers as if you'd written the code yourself, including running it locally. Produce the weekly production release builds and verify rollback before every release. Fix the security findings that come ...

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 ...

brand. Role Responsibilities Develop enterprise class & scalable web applications. Enhance and support existing web application functionality which includes new feature development and resolving complex code issues as reported. Collaborate with subject matter experts, product managers and engineers to build modern, scalable, user friendly and functionally robust web applications … analysing feature requirements. Maintaining and creating product knowledge documentation. Researching and embrace new techniques and technology to improve technology. Uplifting and refactoring of legacy code to modern standards Other duties may be assigned. Focus on quality throughout with strong unit testing. Knowledge, Skills and Experience 3-5 years ...

cloud application for internal fleet monitoring, and a customer-facing fleet administration platform. Two existing mobile apps are to be consolidated, while a legacy desktop product will be maintained only as needed until its support commitments end. What you will be doing Lead, coach and develop the software team … stakeholders. Take ownership of product outcomes, working with Product Management, customers and colleagues to define requirements, prioritise the backlog and shape the roadmap. Lead legacy modernisation and application consolidation, managing older systems through to the end of their support life. Design, build and maintain software across C#/.NET ...

help build, modernise, and support business-critical Windows applications for this fantastic Software Consultancy. If you enjoy C#, SQL Server, system integrations, and transforming legacy code into clean, modern.NET solutions, this is a great opportunity to make a real impact. Work with: C#, .NET/.NET Core, WinForms ...

full development lifecycle. Responsibilities Development & Delivery Design, develop, and maintain backend services and frontend applications for TRG Screen products, including modernisation and maintenance of legacy code. Participate in the full SDLC - requirements analysis, design, implementation, testing, deployment, and post-release support. Operate independently on complex tasks, owning features … across the full stack. Participate in code reviews, providing constructive feedback and ensuring adherence to clean code principles. Troubleshoot and resolve complex software issues across backend and frontend. Use AI tooling as standard practice across design, implementation, code review, and testing to improve quality and delivery speed. ...

delivering great tools with great usability Can work well in a cooperative team environment and has experience dealing with large and/or legacy code bases Ability to work in an agile, cross-functional environment Be able to lead and mentor a team of programmers of various levels ...

engineering role for someone who enjoys solving technically challenging problems. You’ll spend most of your time developing new functionality, alongside targeted work on legacy code, debugging complex issues and continuously improving the quality and maintainability of our software. You’ll collaborate closely with other engineers and internal … design through implementation, testing and delivery. Debug complex issues across development and production environments, driving problems through to resolution. Evolve, maintain and improve existing code, balancing new feature development with targeted brownfield and legacy work. Design and evaluate technical approaches, clearly articulating trade-offs around performance, complexity, maintainability ...

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 ...

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 ...

technically challenging work items, breaking them down into manageable tasks and making sound implementation decisions. Work effectively within an existing, and in some areas legacy codebase, balancing respect for established team practices with thoughtful technical improvement. Demonstrate the potential to lead technical projects. Provide guidance, coaching and technical mentoring ...

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 ...

FPGA Engineer or Senor FPGA Engineer level, depending on the strength of your skills, experience and qualifications. Key Responsibilities: Develop, maintain, and debug HDL code for Xilinx FPGAs in Vivado, implementing full-cycle firmware for Diamond magnet power supplies, including feedback control, filtering, and interlock handling using state machines. … with hardware engineers and the Control Group to optimise performance, resolve issues, and develop reliable Ethernet-based control interfaces. Review, refactor, and document HDL code in line with Diamond standards, ensuring proper version control and maintainability. Contribute to electronic circuit design, simulation (SPICE, MATLAB), PCB design, and prototype testing ...

help build, modernise, and support business-critical Windows applications for this fantastic Software Consultancy. If you enjoy C#, SQL Server, system integrations, and transforming legacy code into clean, modern.NET solutions, this is a great opportunity to make a real impact click apply for full job details ...

experience working across the entire SDLC , with a solid understanding of control algorithms, state machines, and software abstraction layers. Familiar with modifying and refactoring legacy code bases to modern standards. Strong foundation in engineering mathematics and problem-solving from first principles. Experienced in producing technical documentation and maintaining ...

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 ...

your experience and skills can contribute to their success. This will involve working on new features and enhancements, re-architecting, fixing defects and porting legacy code to new technologies. Key Responsibilities Manage a Scrum team developing our Payments software products using agile methodologies. Growing the team skills ...

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 ...