1 to 25 of 30 Remote/Hybrid Legacy Systems Jobs in London

Enterprise Architect (f/m/d)

Hiring Organisation
Awin
Location
London, South East, England, United Kingdom
Employment Type
Full-Time
Salary
Competitive salary
Governance: Develop, maintain, and realize architecture standards and principles that guide technology decisions across the organization. Technology Oversight: Provide strategic oversight of Awin’s systems, platforms, and infrastructure, including legacy systems and cloud-native environments. Integration Leadership: Lead architecture reviews and integration efforts across domains such … experts to ensure architectural consistency and scalability. Strategic Planning: Contribute to long-term planning for platform evolution, including the sunsetting of legacy systems and migration to unified platforms. Mentorship & Enablement: Support solution architects and engineering teams by providing architectural guidance and fostering a culture of technical excellence. ...

Lead PHP Developer {Tech for Good}

Hiring Organisation
Ernest Gordon Recruitment
Location
Enfield, London, United Kingdom
Employment Type
Permanent, Work From Home
Salary
£85,000
With solid groundwork already in place, you will take the lead in defining the technical future, steering the transition from legacy PHP systems to a modern, scalable platform built with Laravel, InertiaJS, and Vue 3. This role would suit an experienced Lead PHP developer experienced with Laravel … ready to step beyond maintaining legacy systems and help build something modern, scalable, and genuinely impactful. The Role: Lead the team and support Full Stack development Take responsibility for legacy PHP systems, ensuring they remain reliable as you progressively build a new platform. Hours ...

UK Life Tax Software Conversion Project Manager

Hiring Organisation
Robert Walters
Location
London, South East, England, United Kingdom
Employment Type
Full-Time
Salary
£400 - £800 per day
needed. Lead a dedicated test team of three to four members, coordinating their activities to ensure thorough validation of outputs between legacy systems and new technology solutions. Support comprehensive testing efforts by collaborating with testers across multiple locations, including the UK and Poland, guaranteeing accuracy and reliability … system outputs. Utilise advanced data analytics skills to compare, reconcile, and validate outputs from legacy systems against those generated by the new platform. Prepare detailed reports for clients or senior management covering incidents, proposals, or other relevant areas as required by operational needs. Attend and contribute meaningfully ...

Senior Backend Engineer (NodeJs/Typescript)

Hiring Organisation
Healthera
Location
City of London, London, United Kingdom
/CD pipelines and developer tooling, while embedding security-by-default, reliability and scalability into the platform. You’ll modernise legacy systems, build new backend capabilities, and make pragmatic engineering decisions that balance delivery speed, quality and long-term maintainability. Core Responsibilities Platform Engineering … reliability, scalability, and cost efficiency through automation and platform standards Backend Engineering Own, maintain, and evolve backend services across legacy and greenfield systems Design and implement scalable backend architectures using Node.js, TypeScript, and NestJS Build and operate RESTful APIs and event-driven systems (queues/topics ...

Data BA

Hiring Organisation
Tenth Revolution Group
Location
London, South East, England, United Kingdom
Employment Type
Contractor
Contract Rate
£400 - £450 per day
modernization program. This is an opportunity to work on a cutting-edge initiative leveraging AI and modern data platforms to transform legacy systems into a future-ready architecture. What You'll Do Phase 1: Foundation & Discovery Legacy Inventory & Triage: Lead discovery of 40-50 legacy ...

Senior C# Developer

Hiring Organisation
Adecco
Location
London, South East, England, United Kingdom
Employment Type
Contractor
Contract Rate
Salary negotiable
side and client-side applications using .NET Framework/Core , React/TypeScript , and relational databases ( SQL Server , Oracle ). Refactor legacy systems to reduce technical debt and improve performance. Implement modern security patterns (OAuth2/OpenID Connect, OWASP principles). Optimise database queries and schemas; ensure ...

Senior C++ Developer Low Latency - Learn Rust

Hiring Organisation
Client Server
Location
London, England, United Kingdom
Senior C++ Developer you will design and develop high throughput backend services for microsecond real-time risk, pricing, trading engines and market making systems, working across the full software development lifecycle using Rust (and some C++ for legacy systems). You'll collaborate with a small … talented team, problem solving and working on complex and challenging systems with interesting work. Location/WFH: You'll join the team in Central London with flexibility to work from home 1-2 days a week. About you: You have strong backend OOP, multithreaded software engineering experience with C++ ...

Senior Platform Engineer - Hedge Fund

Hiring Organisation
Orbis Group
Location
London Area, United Kingdom
data centres and cloud environments. Key focus areas include: Leading the migration from Nomad to Kubernetes across a hybrid infrastructure environment Designing highly available systems that support real-time trading operations Expanding the firm's cloud footprint (AWS/Azure/GCP) while maintaining on-prem capabilities Owning projects … from design through production What you'll need: Production experience with Kubernetes (EKS/AKS/GKE or bare-metal) Strong Linux systems background; Windows experience is beneficial Track record delivering cloud migrations and managing hybrid environments Experience supporting mission-critical, highly available systems What makes this different ...

Back End Integration Engineer

Hiring Organisation
VIQU IT Recruitment
Location
City of London, London, United Kingdom
Employment Type
Contract
Contract Rate
£400 - 500 per day + Inside IR35
digital transformation. Working as part of the Digital Solutions team, you will design, build and maintain APIs, services and integration patterns that connect systems across the business. Back End Integration Engineer's Key Responsibilities Design and implement integrations between internal systems, cloud services and third-party vendor platforms. … work effectively across technical and business teams. Good understanding of data flows, data modelling and system interoperability. Experience integrating with legacy systems and/or third-party vendor platforms. Role Overview: Position : Back End Integration Engineer Type : Contract Location : London – Hybrid – 2/3 days per week ...

Back End Integration Engineer

Hiring Organisation
VIQU IT
Location
London, Broad Street, United Kingdom
Employment Type
Contract
Contract Rate
£400 - £500/day Inside IR35
digital transformation. Working as part of the Digital Solutions team, you will design, build and maintain APIs, services and integration patterns that connect systems across the business. Back End Integration Engineer’s Key Responsibilities Design and implement integrations between internal systems, cloud services and third-party vendor platforms. … work effectively across technical and business teams. Good understanding of data flows, data modelling and system interoperability. Experience integrating with legacy systems and/or third-party vendor platforms. Role Overview: Position : Back End Integration Engineer Type : Contract Location : London – Hybrid – 2/3 days per week ...

Back End Integration Engineer

Hiring Organisation
VIQU IT Recruitment
Location
London, South East, England, United Kingdom
Employment Type
Contractor
Contract Rate
£400 - £500 per day
digital transformation. Working as part of the Digital Solutions team, you will design, build and maintain APIs, services and integration patterns that connect systems across the business. Back End Integration Engineer’s Key Responsibilities Design and implement integrations between internal systems, cloud services and third-party vendor platforms. … work effectively across technical and business teams. Good understanding of data flows, data modelling and system interoperability. Experience integrating with legacy systems and/or third-party vendor platforms. Role Overview: Position : Back End Integration Engineer Type : Contract Location : London – Hybrid – 2/3 days per week ...

C# .NET Core Developer - Hybrid - Banking

Hiring Organisation
GCS
Location
London, United Kingdom
Employment Type
Contract
Contract Rate
£400 - £415/day Inside IR35
Framework/.NET Core, HTML/CSS/TypeScript/React, Python, SQL Server, Oracle). The role focuses on refactoring legacy systems to reduce technical debt, improve reliability and performance, and embed modern security patterns across the service estate. Tasks Design, build, and maintain server-side … TypeScript, Python, and relational databases (SQL Server, Oracle); contribute to API and UI development, data access layers, and integration points. Refactor and modernise legacy codebases: modularisation, dependency updates, performance tuning, improved observability, and raising automated test coverage within CI/CD. Embed modern security patterns and controls across ...

Java Developer

Hiring Organisation
Data Careers
Location
South East London, London, United Kingdom
Employment Type
Permanent, Work From Home
Salary
£75,000
Cleared Java Developer to join a leading technology consultancy working on the upgrade, enhancement, and modernisation of a number of business-critical legacy systems. You will be part of a collaborative Agile delivery team , helping to improve system performance, resilience, and scalability while ensuring continuity for end users. … nature of the work, active SC Clearance is essential . Key Responsibilities Design, develop, and enhance Java-based applications supporting legacy systems Contribute to iterative development within an Agile/Scrum environment Build and consume web services using REST/JSON and XML/SOAP APIs Write ...

Graduate Software Developer / Quantitative Developer / Quantitative Researcher - Up to £180,000 + Bonus + Package

Hiring Organisation
Hunter Bond
Location
London Area, United Kingdom
your career at the intersection of technology, mathematics, and finance ? Join an elite global trading firm where innovation drives everything — no legacy systems, no bureaucracy, just cutting-edge tech and world-class mentorship . You’ll work on greenfield projects from day one, collaborating with exceptional engineers … quants, and researchers to build the systems and models shaping the future of global trading. 🔧 What You’ll Do 🧠 Design and enhance advanced trading systems and analytics platforms 📊 Develop and implement your own quantitative models and research ideas 🤝 Collaborate closely with top technologists, quants, and portfolio managers 🚀 Learn ...

Data Engineer

Hiring Organisation
Inspire People
Location
South Croydon, London, United Kingdom
Employment Type
Permanent, Work From Home
Salary
£40,000
Land Registry (HMLR) is undertaking one of the largest transformation programmes in government, modernising the digital systems that support over £7 trillion of property ownership. As a Data Engineer, you will support the development of HMLR's data engineering capability by helping to build and maintain reliable data pipelines … funding secured and a dedicated Data Engineering capability being formed for the first time, there is a crucial need to build strong, reliable data systems that can support future services and national programmes. As a Data Engineer, you'll work closely with senior data engineering colleagues and multidisciplinary teams ...

Senior Software Engineer (PHP)

Hiring Organisation
True9
Location
South London, UK
Employment Type
Full-time
talented team on our mission to help people and businesses thrive through technology. If you love untangling hard problems, improving legacy systems, and shipping clean, tested code, you'll fit right in. Your role as a Senior PHP Software Engineer at True9: Lead the back-end - write ...

Product Manager

Hiring Organisation
Tiro Partners
Location
London, United Kingdom
Employment Type
Permanent, Work From Home
Salary
£70,000
volume digital commerce business. This role sits at the heart of the product ecosystem, shaping how products, prices, availability and rules flow through complex systems and into customer-facing experiences. Youll work on foundational capabilities rather than surface-level features, helping to create scalable, predictable systems that enable … product, API and data requirements Define scalable product models, pricing logic and configuration rules Own roadmap initiatives that reduce reliance on legacy systems APIs, Data & Integrations Partner with engineering to design and evolve API contracts, data structures and error handling Work closely with suppliers and internal teams ...

Full Stack Software Engineer

Hiring Organisation
Firenze
Location
London Area, United Kingdom
technical depth , gain exposure to DevOps, cloud, and observability practices, and help define how we build software at Firenze. With no legacy systems , you’ll be shaping our platform from the ground up and growing alongside a team that values mentorship, learning, and engineering excellence. Key Responsibilities … pipelines) and learn how to scale reliable delivery. Performance & Observability: Gain hands-on experience with monitoring tools and learn how to build observable systems from day one. Documentation & Developer Experience: Help create clear technical docs and reusable tooling that makes development smoother for everyone. Cross-Functional Collaboration: Partner with ...

Java Developer

Hiring Organisation
Data Careers
Location
London, United Kingdom
Employment Type
Permanent
Salary
GBP 75,000 Annual
Java Developer to join a leading technology consultancy working on the upgrade, enhancement, and modernisation of a number of business-critical legacy systems click apply for full job details ...

Senior Data Migration Manager (Oracle Fusion Cloud)

Hiring Organisation
Circle Group
Location
London, United Kingdom
Employment Type
Contract, Work From Home
Contract Rate
£600 - £700 per day
experience in leading data migration projects for Oracle Fusion Cloud Financial Management , HCM and EPM within a complex legacy environment of source systems, which include Oracle and non-Oracle point systems Proven experience of Oracle master data management products Solid understanding of Fusion data models ...

Software Conversion Project Manager - UK Life Tax

Hiring Organisation
Randstad Technologies
Location
London, South East, England, United Kingdom
Employment Type
Contractor
Contract Rate
£600 - £700 per day
providing regular progress updates.? Oversee data configuration and take-on activities, including strong data analytics skills tocompare, reconcile, and validate outputs from the legacy system to the new platform.? Lead and manage a small test team, coordinating testing efforts across multiple locations.? Ensure all project communications are accurate ...

Lead PHP Developer - Full Stack/Laravel - London

Hiring Organisation
Crimson
Location
London, South East, England, United Kingdom
Employment Type
Full-Time
Salary
£70,000 - £85,000 per annum
role involves hands-on development, technical leadership, architectural oversight, and managing a small team. Responsibilities include setting technical standards, delivering new features, maintaining existing systems, overseeing migration from legacy PHP codebases, and leading new Laravel projects using InertiaJS and Vue 3. The ideal candidate can balance strategy … ensure consistency and robustness of the application architecture. Assume responsibility for the reliability and progressive improvement of legacy PHP systems during platform redevelopment. Collaborate closely with product owners, project managers, and stakeholders to translate business requirements into comprehensive technical plans. Communicate clearly and confidently during client-facing ...

Business Analyst SAP

Hiring Organisation
Fruition Group
Location
South East London, London, United Kingdom
Employment Type
Permanent, Work From Home
Salary
£60,000
expert with a focus on S/4HANA modules including FI, HR, MM, SD, and PS. Support the migration from legacy SAP systems to S/4HANA, including requirements gathering, BPMN process mapping, and data migration activities. Analyse, document, and map business processes and data flows ...

Senior Java Developer

Hiring Organisation
IO Associates
Location
London, United Kingdom
Employment Type
Permanent
Central Government technology programme is looking for an experienced Senior Java Developer to join their high-impact delivery team. Working on mission-critical systems that support national infrastructure, this role offers the chance to work fully remotely on challenging and technically rich work across legacy and modern … Java ecosystem. You will collaborate with developers, testers and DevOps, contribute to automated test reviews, and help maintain and enhance existing legacy systems. You'll also work alongside teams responsible for infrastructure changes using Docker, Ansible, Python, and Linux. Key Requirements Active SC Clearance 5+ years of experience ...

Lead Software Engineer C# / React.js - Top Trading Firm!

Hiring Organisation
Robert Half
Location
London, South East, England, United Kingdom
Employment Type
Full-Time
Salary
Salary negotiable
rebuilding its entire core platform from the ground up greenfield, modern, high-impact. You'll be working directly with the CTO on mission-critical systems used across trading and structured products. What You'll Work On: Full greenfield rebuild of legacy trading systems Modern full-stack … Looking For: Strong C#/.NET engineering background Solid React.js (or modern JS with willingness to grow fast) Experience in financial services/trading systems Ownership mindset - hands-on, ideas-driven, and proactive Interview Process (Fast Turnaround) CTO Intro Live Technical Test HR (Culture & Team Fit) No visas sponsorship ...