Legacy Code Jobs in London

23 of 23 Legacy Code Jobs in London

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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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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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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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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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

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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🚀 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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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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Mobile Application Developer - Mobile, Full Remote, £100k + Equity

West London, UK
Hybrid / WFH Options
Venchr
Founding Engineer - £100k - Remote, AI + Equity What if your next role let you rewrite the rules of mobile connectivity—without ever touching legacy code? We’re looking for a Senior Mobile Developer to join a remote-first team (Europe-based) that’s building the future of mobile carriers from the ground up. This isn’t about patching … build and scale consumer tech. If you’ve built and shipped Flutter apps at scale, and you’re excited by the idea of disrupting an entire industry with elegant code and bold ideas, we’d love to talk. Apply now or reach out if you want to chat more about the role. Venchr is an equal-opportunity employer. All More ❯
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Mobile Application Developer - Mobile, Full Remote, £100k + Equity

Central London, UK
Hybrid / WFH Options
Venchr
Founding Engineer - £100k - Remote, AI + Equity What if your next role let you rewrite the rules of mobile connectivity—without ever touching legacy code? We’re looking for a Senior Mobile Developer to join a remote-first team (Europe-based) that’s building the future of mobile carriers from the ground up. This isn’t about patching … build and scale consumer tech. If you’ve built and shipped Flutter apps at scale, and you’re excited by the idea of disrupting an entire industry with elegant code and bold ideas, we’d love to talk. Apply now or reach out if you want to chat more about the role. Venchr is an equal-opportunity employer. All More ❯
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Mobile Application Developer - Mobile, Full Remote, £100k + Equity

City of London, London, United Kingdom
Hybrid / WFH Options
Venchr
Founding Engineer - £100k - Remote, AI + Equity What if your next role let you rewrite the rules of mobile connectivity—without ever touching legacy code? We’re looking for a Senior Mobile Developer to join a remote-first team (Europe-based) that’s building the future of mobile carriers from the ground up. This isn’t about patching … build and scale consumer tech. If you’ve built and shipped Flutter apps at scale, and you’re excited by the idea of disrupting an entire industry with elegant code and bold ideas, we’d love to talk. Apply now or reach out if you want to chat more about the role. Venchr is an equal-opportunity employer. All More ❯
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Mobile Application Developer - Mobile, Full Remote, £100k + Equity

East London, London, United Kingdom
Hybrid / WFH Options
Venchr
Founding Engineer - £100k - Remote, AI + Equity What if your next role let you rewrite the rules of mobile connectivity—without ever touching legacy code? We’re looking for a Senior Mobile Developer to join a remote-first team (Europe-based) that’s building the future of mobile carriers from the ground up. This isn’t about patching … build and scale consumer tech. If you’ve built and shipped Flutter apps at scale, and you’re excited by the idea of disrupting an entire industry with elegant code and bold ideas, we’d love to talk. Apply now or reach out if you want to chat more about the role. Venchr is an equal-opportunity employer. All More ❯
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Mobile Application Developer - Mobile, Full Remote, £100k + Equity

Central London / West End, London, United Kingdom
Hybrid / WFH Options
Venchr
Founding Engineer - £100k - Remote, AI + Equity What if your next role let you rewrite the rules of mobile connectivity—without ever touching legacy code? We’re looking for a Senior Mobile Developer to join a remote-first team (Europe-based) that’s building the future of mobile carriers from the ground up. This isn’t about patching … build and scale consumer tech. If you’ve built and shipped Flutter apps at scale, and you’re excited by the idea of disrupting an entire industry with elegant code and bold ideas, we’d love to talk. Apply now or reach out if you want to chat more about the role. Venchr is an equal-opportunity employer. All 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

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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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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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)

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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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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Legacy Code
London
10th Percentile
£75,425
25th Percentile
£85,000
Median
£100,000
75th Percentile
£115,000
90th Percentile
£125,000