24 of 24 Permanent Legacy Systems Jobs in the Thames Valley

Data Migration Engineer

Hiring Organisation
Kinetech Recruitment
Location
Milton Keynes, Buckinghamshire, South East, United Kingdom
Employment Type
Permanent, Work From Home
fast-growing, acquisition-led organisation. Your core mission will be to migrate operational (CRM) and in time, finance data from multiple legacy systems into Microsoft Dynamics, repeatedly, reliably, and under pressure. You will work across: Bespoke, undocumented, and at times, home-grown systems SaaS platforms (e.g. … with minimal hand-holding, in a demanding BAU + project environment. What Youll Be Doing For each acquired business, analyse legacy source systems (often undocumented) Understand and interrogate data models at source and target (D365/Dynamics) Perform source-to-target mapping Extract, cleanse, transform, and load ...

Staff Software Engineer

Hiring Organisation
Definely
Location
Slough, Berkshire, UK
Employment Type
Full-time
most complex challenges in our stack. This includes modernising and scaling our .NET backend services, improving system reliability and observability, and designing modular systems that power AI-driven document workflows deeply integrated into Microsoft Word and the broader Microsoft ecosystem. This role is ideal for someone who thrives … designing systems at scale, leading cross functional technical initiatives, and mentoring teams through change. You will have significant influence over technical direction, infrastructure choices, and how we evolve from legacy patterns to a modern, cloud-native architecture. What you'll do: Technical Leadership & Strategy Define and drive ...

Full Stack Engineer

Hiring Organisation
Langham Recruitment
Location
Milton Keynes, Buckinghamshire, UK
Employment Type
Full-time
Software Developer, you'll be part of a dynamic team building and enhancing innovative applications. You'll contribute to modernising legacy systems, scaling core products, and improving overall software quality. Your role will involve: Developing and maintaining backend services using C#, .NET Framework 4.7+, and .NET 6+ ...

Workday Financials Organizational Change and Training Consultant

Hiring Organisation
Cognizant
Location
Slough, Berkshire, UK
Employment Type
Full-time
equipped and confident to adopt new processes Guide clients through the people side of transformation, ensuring a smooth transition from legacy systems to the Workday Financials solution Create engaging training materials, job aids, and communications that resonate with diverse audiences Facilitate workshops and sessions with client stakeholders … equivalent; Bachelor's/Master's degree or professional certification related to Financials Management, Organizational Development, Psychology, Communication Studies, Business Administration, or Management Information Systems a plus Experience with Workday Financials implementations or a Finance based ERP/SaaS transformation projects highly desired 2-5 years Financial software experience ...

Full-Stack Developer

Hiring Organisation
mthree
Location
Slough, Berkshire, UK
Employment Type
Full-time
/Regulatory Technology team within a leading global investment bank working on business-critical regulatory reporting platforms. You'll help modernise legacy systems and build strategic, cloud-based data solutions used across the firm. You'll work in a collaborative Agile squad focused on Java services, Spark ...

Full-Stack Developer

Hiring Organisation
mthree
Location
Oxford, Oxfordshire, UK
Employment Type
Full-time
/Regulatory Technology team within a leading global investment bank working on business-critical regulatory reporting platforms. You'll help modernise legacy systems and build strategic, cloud-based data solutions used across the firm. You'll work in a collaborative Agile squad focused on Java services, Spark ...

Technical Solutions Consultant

Hiring Organisation
IGA Talent Solutions
Location
Milton Keynes, Buckinghamshire, UK
Employment Type
Full-time
recruiting for an experienced Technical Consultant to support a complex banking accreditation and compliance programme for a retail organisation. Key responsibilities include: Reviewing existing systems, processes, and documentation against banking accreditation standards Performing functional and technical gap analysis, owning remediation recommendations Reverse engineering legacy applications to understand … transactional data generation and file outputs consumed by banking systems Assessing payment, security, and integration solutions for compliance Supporting legacy system enhancement vs replacement decision-making Required experience: Knowledge of banking accreditation, PCI DSS/payment compliance COBOL, CICS, Datacom DB Ability to translate regulatory and technical ...

Head of Architecture - Infrastructure

Hiring Organisation
Centrica - CHP
Location
Windsor, Berkshire, South East, United Kingdom
Employment Type
Permanent, Work From Home
guiding the architectural vision across our Infrastructure business. This role sits at the heart of a product-led technology organisation, ensuring that our systems and platforms not only support current business needs but are also built to scale and evolve with future demands. You'll be the strategic mind … behind long-term technology roadmaps, aligning them with enterprise architecture and the wider technology strategy. Whether it's rationalising legacy systems or guiding future investments, your focus will be on creating a technology landscape that's efficient, secure, and ready for growth. Location: UK-based hybrid role ...

Software Engineer

Hiring Organisation
mthree
Location
High Wycombe, Buckinghamshire, UK
Employment Type
Full-time
/Regulatory Technology team within a leading global investment bank. You'll work on business-critical regulatory reporting platforms, helping modernise legacy systems and build strategic, cloud-based data solutions used across the firm. You'll be part of a collaborative Agile squad focused on Java services ...

Software Engineer

Hiring Organisation
mthree
Location
Oxford, Oxfordshire, UK
Employment Type
Full-time
/Regulatory Technology team within a leading global investment bank. You'll work on business-critical regulatory reporting platforms, helping modernise legacy systems and build strategic, cloud-based data solutions used across the firm. You'll be part of a collaborative Agile squad focused on Java services ...

Software Engineer (Data) (6 month contract)

Hiring Organisation
Arcus Search
Location
Slough, Berkshire, UK
Employment Type
Full-time
data quality, performance, and maintainability Tech environment • Kotlin & Spring Boot for core data processing services • Python for tooling and automation • Legacy systems in C# and Scala/Spark • Exposure to data lakes and large-scale data platforms is a strong plus What they're looking for • Strong … background (Kotlin, Java, or Scala) • Experience building or modernising data pipelines • Solid understanding of SQL and data processing systems • Comfortable working in complex, performance-sensitive environments • Financial markets or trading data experience is beneficial but not essential 6-month initial contract with potential to extend. Onsite by default, with ...

Genetec Security Engineer

Hiring Organisation
QCIC
Location
Slough, Berkshire, UK
Employment Type
Full-time
control and CCTV projects across the client's portfolio. This position will involve supporting enterprise-level application implementations, managing migrations from legacy systems, and providing expert troubleshooting. The ideal candidate must excel in multitasking and thrive in a fast-paced, dynamic environment. This is an on-site … Oversee and execute the system configuration of the C-Cure and Victor servers for adding new or modifying existing installations Process the administration of systems, providing a robust triage service through a 24/7 Command Centre for all reported technical issues and manage any subsequent requirement and fault ...

Data Architect

Hiring Organisation
Connells Group HQ
Location
Caldecotte, Milton Keynes, Buckinghamshire, England, United Kingdom
Employment Type
Full-Time
Salary
Competitive salary
Hybrid Integration Design: Lead the design and implementation of data solutions that integrate Azure cloud-native services with legacy SQL Server systems and third-party APIs and data feeds. Data Modelling and Standards: Develop and enforce data modelling standards (conceptual, logical, physical) across platforms. Promote reuse, consistency … decisions. Experience and Skills Required: Experience with Data Architecture and governance, public-cloud platforms (Azure, AWS, GCP) , SQL Server, data integration with third-party systems, ideally Microsoft Fabric Experience with data modelling and metadata management Relevant degree or post-graduate qualification, ideally certification in Cloud Architecture and Data Management ...

Principal Backend Engineer - Matchmaking

Hiring Organisation
ESL FACEIT Group - EFG
Location
Reading, Berkshire, UK
Employment Type
Full-time
elite individual contributor who can look at this scale not just as a traffic challenge, but as an abstraction challenge. You will design the systems that define how our players compete, ensuring our architecture is decoupled, extensible, and capable of handling the next 100 million users. What You Will … designing, developing, and deploying robust APIs and microservices in production. Golang experience is highly preferred; Architectural Vision: Proven experience re-architecting legacy systems into distributed, modern microservices. You understand Domain-Driven Design (DDD) and know how to draw the boundaries between services correctly; Scaling Instincts: You understand ...

Principal Backend Engineer - Matchmaking

Hiring Organisation
ESL FACEIT Group - EFG
Location
Milton Keynes, Buckinghamshire, UK
Employment Type
Full-time
elite individual contributor who can look at this scale not just as a traffic challenge, but as an abstraction challenge. You will design the systems that define how our players compete, ensuring our architecture is decoupled, extensible, and capable of handling the next 100 million users. What You Will … designing, developing, and deploying robust APIs and microservices in production. Golang experience is highly preferred; Architectural Vision: Proven experience re-architecting legacy systems into distributed, modern microservices. You understand Domain-Driven Design (DDD) and know how to draw the boundaries between services correctly; Scaling Instincts: You understand ...

Lead Security Engineer

Hiring Organisation
OutSystems
Location
Oxford, Oxfordshire, UK
Employment Type
Full-time
strategy. Define and implement security standards, policies, and best practices for cloud infrastructure, SaaS applications, and internal tooling. Engineer, implement, and continuously tune security systems (SIEM, EDR, etc.) for continuous threat detection and automated response. Lead technical remediation efforts, working with engineering teams to implement fixes for vulnerabilities … automation skills (e.g. Python, PowerShell, Terraform scripts, Yara) to implement security automations, detection rules, and guardrails. Solid experience with designing, implementing, and tuning systems for incident response, detection engineering, and vulnerability management. Strong understanding of secure software development lifecycle (SDLC), and ability to work closely with dev/ ...

Lead Security Engineer

Hiring Organisation
OutSystems
Location
High Wycombe, Buckinghamshire, UK
Employment Type
Full-time
strategy. Define and implement security standards, policies, and best practices for cloud infrastructure, SaaS applications, and internal tooling. Engineer, implement, and continuously tune security systems (SIEM, EDR, etc.) for continuous threat detection and automated response. Lead technical remediation efforts, working with engineering teams to implement fixes for vulnerabilities … automation skills (e.g. Python, PowerShell, Terraform scripts, Yara) to implement security automations, detection rules, and guardrails. Solid experience with designing, implementing, and tuning systems for incident response, detection engineering, and vulnerability management. Strong understanding of secure software development lifecycle (SDLC), and ability to work closely with dev/ ...

Lead Security Engineer

Hiring Organisation
OutSystems
Location
Milton Keynes, Buckinghamshire, UK
Employment Type
Full-time
strategy. Define and implement security standards, policies, and best practices for cloud infrastructure, SaaS applications, and internal tooling. Engineer, implement, and continuously tune security systems (SIEM, EDR, etc.) for continuous threat detection and automated response. Lead technical remediation efforts, working with engineering teams to implement fixes for vulnerabilities … automation skills (e.g. Python, PowerShell, Terraform scripts, Yara) to implement security automations, detection rules, and guardrails. Solid experience with designing, implementing, and tuning systems for incident response, detection engineering, and vulnerability management. Strong understanding of secure software development lifecycle (SDLC), and ability to work closely with dev/ ...

Data Migration Analyst (IT) / Contractor

Hiring Organisation
Free-Work UK
Location
Milton Keynes, Buckinghamshire, UK
Employment Type
Full-time
least 3 to 5 years experience as a Data Analyst. Provide support to the data migration Lead in the data migration of legacy data into NetSuite edERP in accordance with the project plan Review the legacy data to identify data quality issues Review non-legacy … required. Must have at least 3 to 5 years experience of data analysing and/or cleansing and at least 3+ years experience of systems implementation. Have experience of extraction & cleansing of legacy data. Being involved in at least 2 major Data migration projects. Should have strong ...

Senior Application Support Analyst

Hiring Organisation
Randstad Digital
Location
Oxford, Oxfordshire, UK
Employment Type
Full-time
sessions (sequence gaps, rejects, drops) Work with Network and Infrastructure teams on VPNs and cross-connects Support migration of legacy trading systems Required Experience 3–5 years in FIX Connectivity, Integration, or Trading Production Support Strong FIX Protocol knowledge (session & application layers) Linux/Unix experience with ...

Senior Application Support Analyst

Hiring Organisation
Randstad Digital
Location
Slough, Berkshire, UK
Employment Type
Full-time
sessions (sequence gaps, rejects, drops) Work with Network and Infrastructure teams on VPNs and cross-connects Support migration of legacy trading systems Required Experience 3–5 years in FIX Connectivity, Integration, or Trading Production Support Strong FIX Protocol knowledge (session & application layers) Linux/Unix experience with ...

Senior Systems Engineer

Hiring Organisation
Legal 500
Location
Oxford, Oxfordshire, UK
Employment Type
Full-time
this depth of global research and data on law firms, lawyers and their clients. About the Role We're looking for a Senior Systems Engineer to take ownership of our modern cloud environment and lead key infrastructure projects. This is a hands-on technical role where you'll design … deliver practical solutions across Microsoft 365,Azure/Entra ID, and core infrastructure, while helping us retire legacy systems. You'll act as a role model for junior engineers and play a pivotal part in shaping our technology roadmap. What You'll Do Lead administration and optimisation ...

Oracle Developer

Hiring Organisation
4Square Recruitment Ltd
Location
Slough, Berkshire, England, United Kingdom
Employment Type
Full-Time
Salary
£60,000 - £70,000 per annum
performance, scalable database solutions. This is a hands-on role for someone who genuinely enjoys writing proper PL/SQL—not just babysitting legacy code. What You’ll Need 10+ years’ commercial experience working with Oracle PL/SQL Strong, clean, and efficient Oracle SQL & PL/… similar fast-paced environment Nice to Have (but not deal-breakers) Performance tuning and query optimisation Experience supporting or refactoring legacy Oracle systems Exposure to modern development practices and version control ...

Lead Software Engineer (C#/.React.js) -TOP TRADING COMPANY!

Hiring Organisation
Robert Half
Location
Slough, Berkshire, UK
Employment Type
Full-time
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 ...