Legacy Code Jobs in London

25 of 25 Legacy Code Jobs in London

Senior Software Engineer

City of London, London, United Kingdom
Burns Sheehan
to attract the best talent on the market. Having received huge investment, they are on a journey to truly disrupt the industry and are not held back by any legacy code or old customers. This means that they're able to build out state-of-the-art, Greenfield code which can focus on being the worlds most More ❯
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Senior Software Engineer

London Area, United Kingdom
Burns Sheehan
to attract the best talent on the market. Having received huge investment, they are on a journey to truly disrupt the industry and are not held back by any legacy code or old customers. This means that they're able to build out state-of-the-art, Greenfield code which can focus on being the worlds most More ❯
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Lead Software Engineer

London Area, United Kingdom
Burns Sheehan
to attract the best talent on the market. Having received huge investment, they are on a journey to truly disrupt the industry and are not held back by any legacy code or old customers. This means that they're able to build out state-of-the-art, Greenfield code which can focus on being the worlds most More ❯
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Lead Software Engineer

City of London, London, United Kingdom
Burns Sheehan
to attract the best talent on the market. Having received huge investment, they are on a journey to truly disrupt the industry and are not held back by any legacy code or old customers. This means that they're able to build out state-of-the-art, Greenfield code which can focus on being the worlds most More ❯
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Senior Software Engineer

City of London, London, United Kingdom
bloom
minded and love solving messy, complex problems You thrive in small teams where ideas move from whiteboard → production in hours You want to build something meaningful, not just maintain legacy code, with a love for building 0-1 products. 📍 London (4 days a week building together onsite) 💰 Up to £130,000 + meaningful early-stage equity % If you More ❯
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Senior Software Engineer

London Area, United Kingdom
bloom
minded and love solving messy, complex problems You thrive in small teams where ideas move from whiteboard → production in hours You want to build something meaningful, not just maintain legacy code, with a love for building 0-1 products. 📍 London (4 days a week building together onsite) 💰 Up to £130,000 + meaningful early-stage equity % If you More ❯
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Software Engineer

City of London, London, United Kingdom
LinuxRecruit
is discovered, protected, and accelerated. The 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 respected technology companies and More ❯
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Software Engineer

London Area, United Kingdom
LinuxRecruit
is discovered, protected, and accelerated. The 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 respected technology companies and More ❯
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🚀 C++ Engineer – World’s Largest (Almost!) Supercomputer

City of London, London, United Kingdom
Augmentti
by colleagues who are at the top of their fields, pushing the boundaries of technology and finance every day. Innovation & Impact: Work in a modern, young codebase with minimal legacy code and technical debt. You’ll have the freedom to choose the best technology for the job, allowing you to innovate and deliver at an unmatched scale. They More ❯
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🚀 C++ Engineer – World’s Largest (Almost!) Supercomputer

London Area, United Kingdom
Augmentti
by colleagues who are at the top of their fields, pushing the boundaries of technology and finance every day. Innovation & Impact: Work in a modern, young codebase with minimal legacy code and technical debt. You’ll have the freedom to choose the best technology for the job, allowing you to innovate and deliver at an unmatched scale. They More ❯
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Digital Web Manager

Bromley, London, United Kingdom
Bromcom Computers Plc
CMS governance, analytics setup (GA4, GTM), and integration with Dynamics 365 and Power BI. Own website performance, accessibility, and SEO optimisation. Oversee ongoing maintenance, updates, and documentation to avoid legacy code issues. Skills & Experience Essential Experience leading website redevelopment or CMS migration projects. Knowledge of CMS platforms such as Optimizely, Umbraco, or WordPress. Working knowledge of HTML, CSS More ❯
Employment Type: Permanent
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SAP ABAP Developer

London Area, United Kingdom
LJRecruitment
accelerate transformation, and finally bring clarity to complex systems. The role Take your SAP and ABAP experience into a next-generation environment where the focus isn’t on maintaining legacy code, but on building smarter ways of understanding and improving enterprise systems . You’ll collaborate with a small, ambitious team blending deep technical know-how with automation More ❯
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SAP ABAP Developer

City of London, London, United Kingdom
LJRecruitment
accelerate transformation, and finally bring clarity to complex systems. The role Take your SAP and ABAP experience into a next-generation environment where the focus isn’t on maintaining legacy code, but on building smarter ways of understanding and improving enterprise systems . You’ll collaborate with a small, ambitious team blending deep technical know-how with automation More ❯
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ABAP Developer - AI Product - London - Permanent

City of London, London, United Kingdom
LJ Recruitment Limited
accelerate transformation, and finally bring clarity to complex systems. The role: Take your SAP and ABAP experience into a next-generation environment where the focus isn't on maintaining legacy code, but on building smarter ways of understanding and improving enterprise systems . You'll collaborate with a small, ambitious team blending deep technical know-how with automation More ❯
Employment Type: Permanent
Salary: £90,000
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Quantitative Developer

London Area, United Kingdom
Cititec
doing: Designing, developing, and maintaining pricing libraries for commodity products Building and supporting risk management tools and analytics platforms Taking models from prototype to production - writing robust, scalable Python code Collaborating with quantitative analysts to implement models and frameworks Interacting with some legacy codebases, ideally in another OOP language (C C#/Java) What they’re looking for … Solid professional experience as a Quant Developer (or software developer with mathematical background) Strong programming skills in Python, with the ability to write production-grade code Experience with at least one other OOP language (C++, C#, or Java) Background in commodities trading, risk, or pricing Familiarity with numerical libraries, performance optimisation, and clean software design principles Confident working closely More ❯
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Quantitative Developer

City of London, London, United Kingdom
Cititec
doing: Designing, developing, and maintaining pricing libraries for commodity products Building and supporting risk management tools and analytics platforms Taking models from prototype to production - writing robust, scalable Python code Collaborating with quantitative analysts to implement models and frameworks Interacting with some legacy codebases, ideally in another OOP language (C C#/Java) What they’re looking for … Solid professional experience as a Quant Developer (or software developer with mathematical background) Strong programming skills in Python, with the ability to write production-grade code Experience with at least one other OOP language (C++, C#, or Java) Background in commodities trading, risk, or pricing Familiarity with numerical libraries, performance optimisation, and clean software design principles Confident working closely More ❯
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Software Engineer (Remote/Hybrid)

Central London, UK
Hybrid/Remote Options
Secure Screening Services
heights. · High Levels of Collaboration: Engage in high levels of collaboration with a team that values teamwork, open communication, and collective problem-solving. Duties & Responsibilities · Deliver stable, well-reviewed code across our PHP 8/Laravel 9 monolith · Improve legacy systems incrementally without introducing risk or churn · Follow technical leadership and prioritize team goals over personal agendas · Mentor … engineering environment Skills & Qualifications · 5+ years of professional experience with PHP/Laravel in production · Strong familiarity with Laravel conventions and the broader ecosystem · Proven ability to work within legacy codebases · Competence with React — no rebuilds, but capable of debugging and stabilizing · Experience with DevOps basics: AWS, CI/CD, shell tools, etc. · High attention to detail and careful More ❯
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Software Engineer (Remote/Hybrid)

West London, UK
Hybrid/Remote Options
Secure Screening Services
heights. · High Levels of Collaboration: Engage in high levels of collaboration with a team that values teamwork, open communication, and collective problem-solving. Duties & Responsibilities · Deliver stable, well-reviewed code across our PHP 8/Laravel 9 monolith · Improve legacy systems incrementally without introducing risk or churn · Follow technical leadership and prioritize team goals over personal agendas · Mentor … engineering environment Skills & Qualifications · 5+ years of professional experience with PHP/Laravel in production · Strong familiarity with Laravel conventions and the broader ecosystem · Proven ability to work within legacy codebases · Competence with React — no rebuilds, but capable of debugging and stabilizing · Experience with DevOps basics: AWS, CI/CD, shell tools, etc. · High attention to detail and careful More ❯
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Software Engineer (Remote/Hybrid)

City of London, London, United Kingdom
Hybrid/Remote Options
Secure Screening Services
heights. · High Levels of Collaboration: Engage in high levels of collaboration with a team that values teamwork, open communication, and collective problem-solving. Duties & Responsibilities · Deliver stable, well-reviewed code across our PHP 8/Laravel 9 monolith · Improve legacy systems incrementally without introducing risk or churn · Follow technical leadership and prioritize team goals over personal agendas · Mentor … engineering environment Skills & Qualifications · 5+ years of professional experience with PHP/Laravel in production · Strong familiarity with Laravel conventions and the broader ecosystem · Proven ability to work within legacy codebases · Competence with React — no rebuilds, but capable of debugging and stabilizing · Experience with DevOps basics: AWS, CI/CD, shell tools, etc. · High attention to detail and careful More ❯
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Software Engineer (Remote/Hybrid)

East London, London, United Kingdom
Hybrid/Remote Options
Secure Screening Services
heights. · High Levels of Collaboration: Engage in high levels of collaboration with a team that values teamwork, open communication, and collective problem-solving. Duties & Responsibilities · Deliver stable, well-reviewed code across our PHP 8/Laravel 9 monolith · Improve legacy systems incrementally without introducing risk or churn · Follow technical leadership and prioritize team goals over personal agendas · Mentor … engineering environment Skills & Qualifications · 5+ years of professional experience with PHP/Laravel in production · Strong familiarity with Laravel conventions and the broader ecosystem · Proven ability to work within legacy codebases · Competence with React — no rebuilds, but capable of debugging and stabilizing · Experience with DevOps basics: AWS, CI/CD, shell tools, etc. · High attention to detail and careful More ❯
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Software Engineer (Remote/Hybrid)

Central London / West End, London, United Kingdom
Hybrid/Remote Options
Secure Screening Services
heights. · High Levels of Collaboration: Engage in high levels of collaboration with a team that values teamwork, open communication, and collective problem-solving. Duties & Responsibilities · Deliver stable, well-reviewed code across our PHP 8/Laravel 9 monolith · Improve legacy systems incrementally without introducing risk or churn · Follow technical leadership and prioritize team goals over personal agendas · Mentor … engineering environment Skills & Qualifications · 5+ years of professional experience with PHP/Laravel in production · Strong familiarity with Laravel conventions and the broader ecosystem · Proven ability to work within legacy codebases · Competence with React — no rebuilds, but capable of debugging and stabilizing · Experience with DevOps basics: AWS, CI/CD, shell tools, etc. · High attention to detail and careful More ❯
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Software Engineer

London Area, United Kingdom
RJC Group
platform by developing data-driven solutions, collaborating across teams, and working on their in-house trading system. Responsibilities: Build reusable data components connecting external sources and internal tools Modernize legacy codebases to Python Translate business needs into technical solutions Maintain code quality and documentation Collaborate with global teams and stakeholders Requirements: 3+ years Python experience SQL (Oracle/ More ❯
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Software Engineer

City of London, London, United Kingdom
RJC Group
platform by developing data-driven solutions, collaborating across teams, and working on their in-house trading system. Responsibilities: Build reusable data components connecting external sources and internal tools Modernize legacy codebases to Python Translate business needs into technical solutions Maintain code quality and documentation Collaborate with global teams and stakeholders Requirements: 3+ years Python experience SQL (Oracle/ More ❯
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Principal Consultant (AI/ML)

City of London, London, United Kingdom
Areti Group | B Corp™
is seeking a Principal AI/ML Consultant to lead strategic technical transformation within a financial services environment. This is a hands-on, client-facing role focused on modernising legacy systems, driving AI adoption, and delivering measurable business value. Key Responsibilities Lead the systematic modernisation of legacy services, prioritising based on business impact. Eliminate technical debt by extracting … APIs, decommissioning obsolete services, and consolidating functionality. Collaborate with engineering teams to identify and deliver high-impact modernisation opportunities. Support platform services strategy by transforming legacy services into reusable, shared components. Drive adoption of AI tooling (e.g., Claude Code, GitHub Copilot) to accelerate development and modernisation. Create playbooks and replicable patterns for AI-enabled development and modernisation. Use … LLMs and AI for service discovery, dependency mapping, code analysis, refactoring, and documentation. Demonstrate and quantify business value from AI adoption. Ensure modernised services are handed off with clear ownership and integrated into new workflows. Skills & Experience Proven experience leading technical teams and modernising complex legacy systems at scale. Strong architectural skills and ability to design logical abstractions More ❯
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Principal Consultant (AI/ML)

London Area, United Kingdom
Areti Group | B Corp™
is seeking a Principal AI/ML Consultant to lead strategic technical transformation within a financial services environment. This is a hands-on, client-facing role focused on modernising legacy systems, driving AI adoption, and delivering measurable business value. Key Responsibilities Lead the systematic modernisation of legacy services, prioritising based on business impact. Eliminate technical debt by extracting … APIs, decommissioning obsolete services, and consolidating functionality. Collaborate with engineering teams to identify and deliver high-impact modernisation opportunities. Support platform services strategy by transforming legacy services into reusable, shared components. Drive adoption of AI tooling (e.g., Claude Code, GitHub Copilot) to accelerate development and modernisation. Create playbooks and replicable patterns for AI-enabled development and modernisation. Use … LLMs and AI for service discovery, dependency mapping, code analysis, refactoring, and documentation. Demonstrate and quantify business value from AI adoption. Ensure modernised services are handed off with clear ownership and integrated into new workflows. Skills & Experience Proven experience leading technical teams and modernising complex legacy systems at scale. Strong architectural skills and ability to design logical abstractions More ❯
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Legacy Code
London
10th Percentile
£75,425
25th Percentile
£85,000
Median
£100,000
75th Percentile
£115,000
90th Percentile
£125,000