Legacy modernisation: Future-proof your business systems

Outdated legacy systems can hinder growth, increase operational costs, and expose your business to security risks – including UK regulatory and compliance violations. We specialise in modernising these core systems, transforming them into agile, efficient, and scalable assets. Led by Oracle ACE Director Matt Mulvaney, based in London.

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Learn about Pretius UK

Led by Oracle ACE Director Matt Mulvaney

Our UK operations are led by Matt Mulvaney — one of only 17 Oracle ACE Directors in the world — based in London. Every legacy modernisation engagement receives direct architectural oversight from Matt, ensuring your chosen path is future-proof, commercially sound, and aligned with UK regulatory requirements. All work is governed by English Law through Pretius Ltd, a fully registered UK entity (Company No: 147557660).

Matt Mulvaney

Pretius Ltd CEO / London-based leadership

♠ Oracle ACE Director — 1 of 17 worldwide

Why legacy modernisation can no longer wait for UK enterprises

For many British organisations, the legacy system question is no longer a technology conversation — it is a regulatory and competitive one. The pressures converging on UK businesses with ageing core systems are more acute than ever:

DORA (Digital Operational Resilience Act)

In force since January 2025, requires financial services firms to demonstrate ICT resilience with documented, tested DR capabilities. Legacy systems on unsupported platforms cannot satisfy these requirements.

FCA operational resilience rules

Require firms to identify important business services and prove they can remain within impact tolerances even during severe but plausible disruption. A system that cannot be patched or updated is a documented vulnerability.

UK GDPR

Requires ongoing technical and organisational measures to protect personal data. Running critical business logic on unsupported, unpatched software is increasingly difficult to justify to the ICO.

The talent pool is shrinking

Developers who know COBOL, Oracle Forms, legacy .NET, or early Java stacks are retiring faster than organisations can replace them. The cost of finding and retaining legacy skills in the UK market is rising sharply every year.

Every competitor who has modernised

Can build and deploy features in days that take your team months. The gap compounds.

The question for UK CTOs and CIOs is no longer whether to modernise. It is which approach minimises risk while delivering the most value, and who is qualified to help them execute it.

Our core modernisation capabilities

01 Legacy system assessment & strategy

At Pretius, we analyse your existing legacy applications — including those built with Oracle Forms, Discoverer, OBIEE, legacy .NET, Java, COBOL, or early PHP — to understand their business criticality, technological state, and pain points. We also assess your organisation's overall situation: available resources, databases in use, team capabilities, and specific business and regulatory needs.

This analysis informs a recommendation on the most suitable path forward: whether migration is necessary, which technology stack would deliver the greatest value, and what the realistic scope, timeline, and cost of modernisation looks like.

A roadmap aligned with your strategic goals

Based on this analysis, we develop a tailored modernisation roadmap aligned with your strategic goals — whether it involves re-platforming, re-hosting, re-engineering, or complete rebuilding. For UK-regulated organisations, the roadmap explicitly addresses compliance implications at each phase, so regulators and auditors can see a credible, evidence-based transition plan.

02 Platform and technology migration

Pretius expertly migrates your applications from outdated platforms to modern environments. This includes:

Upgrading underlying technologies — for example, moving from older database versions to current, vendor-supported releases
Transitioning to more efficient technology stacks — replacing Oracle Forms or OBIEE with Oracle APEX-based alternatives, or moving legacy .NET and Java applications to modern frameworks
Migrating from legacy SaaS platforms — Salesforce, Microsoft Dynamics, or Lotus Notes/Domino — to bespoke, owned alternatives

The results across our delivered projects consistently include reduced licensing costs, improved user experience, enhanced functionality, and significantly easier maintenance.

Real outcomes from our legacy migration projects

Munich Re HealthTech: Rating reserves and data mapping processes that previously took up to 15 days using Excel now take approximately 20 minutes — a transformation achieved in 4 months.
Sweco: Deployment of new features and updates shortened from several months to just a few minutes, enabling faster delivery to 120+ municipal clients.
Van Cargo: Automatic calculation of freight rates allows the company to react much faster to attractive transport assignments, eliminating manual workarounds.

03 Application re-engineering & refactoring

We re-engineer or refactor your legacy applications — in part or in full — to improve their architecture, code quality, performance, scalability, and maintainability. This may involve:

Breaking down monolithic applications into microservices, enabling independent deployment and reducing the blast radius of any single failure.
Improving database structures to support faster queries, better auditability, and modern data governance requirements.
Optimising inefficient code that has accumulated over years of ad-hoc fixes and short-term workarounds.

Consolidating into a unified, modern platform

This approach enables organisations to consolidate disparate systems into a unified, modern platform — improving data consistency, streamlining workflows, and providing a single source of truth. As a concrete example, we helped T-Mobile replace three separate legacy systems with a single, efficient microservice-based architecture — delivering better performance, lower maintenance overhead, and a significantly improved experience for sales consultants serving 11 million customers.

For UK financial services organisations, this kind of consolidation also simplifies compliance: fewer systems means fewer audit surfaces, fewer data flows to map under UK GDPR, and fewer integration points to test under DORA's resilience requirements.

04 Data modernisation & migration

Pretius assists organisations in comprehensively modernising their data landscape. This involves not just migrating from legacy databases — which are frequently complex, siloed, and poorly documented — but also transforming and optimising the underlying data structures.

We implement modern data warehousing solutions and build efficient data pipelines to ensure quality, consistency, and accessibility across your organisation.

Enabling advanced analytics and new capabilities

A modernised data foundation is critical for enabling advanced analytics, powering new applications, supporting business intelligence initiatives, and deriving actionable insights for informed decision-making. It also establishes the clean, auditable data lineage that UK GDPR and FCA data governance requirements demand — making data subject access requests, regulatory reporting, and audit responses significantly more manageable.

05 Integration with modern systems

We ensure your modernised applications are fully connected to your broader IT environment — current systems, third-party services, and APIs — guaranteeing efficient data flow and operational continuity throughout and after the transition.

Effective integration, alongside potential re-engineering efforts, enables the consolidation of disparate systems for genuinely improved business processes.

For UK organisations with hybrid IT estates — a mix of cloud SaaS, on-premise legacy, and bespoke applications — this integration layer is often what determines whether a modernisation delivers its promised ROI or creates new silos.

06 Cloud modernisation & migration

We help organisations leverage the benefits of the cloud by modernising and migrating legacy applications to Oracle Cloud Infrastructure (OCI), Amazon Web Services (AWS), Google Cloud Platform (GCP), or Microsoft Azure.

This can involve re-hosting applications for infrastructure-as-a-service (IaaS) benefits, or re-architecting for cloud-native capabilities including elastic scaling, managed database services, and serverless computing.

For UK-regulated organisations with data sovereignty requirements — financial services firms under FCA rules, public sector organisations under UK data residency obligations, or businesses subject to DORA's geographic concentration requirements — we design cloud deployments that satisfy these constraints from the outset, not as an afterthought.

Cloud modernisation in practice

The TVN Warner Bros. Discovery VOD platform migration to AWS prepared the platform for over 60 million monthly viewers — demonstrating how cloud modernisation contributes directly to scalability and performance at enterprise scale.

For Oracle-centric UK organisations, OCI offers the additional benefit of eliminating the 2:1 core factor licensing penalty that applies on AWS and Azure, producing measurable cost reductions for existing Oracle licence holders.

The modernisation strategies we apply

We offer a range of strategies tailored to your specific system, budget, and risk appetite. These are not theoretical categories — each represents a distinct approach we have executed in production:

Strategy

What it means

When it applies

Re-hosting

Moving the application to new infrastructure with minimal changes

Reducing infrastructure costs quickly, buying time for deeper modernisation

Re-platforming

Migrating to a new platform with targeted improvements

Moving Oracle workloads to OCI; transitioning Forms to APEX

Refactoring

Restructuring existing code without changing its external behaviour

Improving maintainability and performance without a full rewrite

Re-architecting

Altering the codebase to shift to a new architecture

Breaking monoliths into microservices; adding cloud-native capabilities

Rebuilding

Redesigning and developing the application from scratch

When the legacy system's architecture is too constrained to extend

Replacing

Substituting with a suitable off-the-shelf or custom solution

When a purpose-built replacement delivers better ROI than modernising the existing system

Our assessment phase identifies which strategy – or combination of strategies – best fits your situation. We do not recommend re-platforming when a refactor is sufficient, and we do not recommend a rebuild when a targeted re-architecture will achieve the same outcome at lower risk.

What legacy systems we modernise

We have delivered modernisation projects across a wide range of legacy stacks. Common source environments include:

Oracle Forms and Reports

Migrated to Oracle APEX, preserving PL/SQL business logic while eliminating the Java applet dependency and WebLogic middleware overhead.

Oracle OBIEE and Discoverer

Replaced with modern analytics and reporting platforms, including Oracle APEX Interactive Grids and custom dashboards.

Legacy .NET and Java applications

Re-architected into microservice or modern web frameworks, frequently with Oracle or PostgreSQL backends.

Legacy PHP and early web applications

Rebuilt on scalable, secure modern stacks aligned with the organisation's existing team skills.

Salesforce and Microsoft Dynamics

Replaced with bespoke CRM systems that eliminate per-user licensing fees and vendor lock-in.

Lotus Notes and Domino

Migrated to cloud-ready, DORA-compliant, mobile-first ecosystems.

Excel and spreadsheet-based processes

Transformed into governed, auditable APEX applications with proper access control and data integrity enforcement.

For Oracle Forms specifically, we have invested in proprietary AI-assisted tooling — the Pretius AI Forms to APEX Assistant — that achieves approximately 90% accuracy on effort estimation and significantly accelerates the semi-automated conversion of core PL/SQL logic.

The Pretius UK advantage

Sovereign ACE leadership

Pretius Ltd is a fully registered UK entity (Company No: 147557660) headquartered in London. Oracle ACE Director Matt Mulvaney provides direct architectural oversight on all UK engagements, ensuring modernisation plans meet the highest institutional standards and UK-specific compliance requirements including FCA, DORA, and UK GDPR.

Local UK contracts governed by English Law
FCA / DORA compliance built into modernisation planning, not retrofitted
UK GDPR and Data Protection Act alignment throughout
100% IR35-compliant B2B engagement

Instant enterprise scale

In a market where specialist legacy modernisation talent is scarce — particularly for Oracle, COBOL, and early Java stacks — we provide immediate access to 300+ in-house salaried specialists.

Senior squads deployable within two weeks
5 Oracle ACEs covering database, APEX, and cloud architecture
No recruitment delays, no IR35 exposure
Unified delivery standards across the entire team

London–Warsaw hybrid model

Strategic consulting and project governance from our London office, combined with the engineering scale of our Warsaw Centre of Excellence — delivering high-end legacy modernisation capability at a significant cost advantage compared to purely London-based consultancies.

Matt Mulvaney-led UK strategy and stakeholder engagement
Time-zone aligned collaboration throughout the project
Oracle UK Sovereign Cloud, AWS, and Azure expertise
24/7 managed services and SLA-backed support post-migration

Technology-agnostic recommendation

We are Oracle experts. We are also Java developers, .NET engineers, React architects, and PostgreSQL specialists. That breadth means we have no structural reason to push any one platform. Our recommendation follows your data, your team, and your strategy — not our commercial preferences.

Value-driven approach

Our focus extends beyond code. We collaborate closely with British business and technology leaders to ensure every modernisation project delivers measurable ROI — reduced licensing costs, faster feature delivery, lower maintenance overhead, and systems that pass regulatory scrutiny rather than failing it.

Phased delivery — No big bang

We do not recommend turning off the old system and turning on the new one over a weekend. Our phased approach allows old and new systems to run in parallel on the same underlying data, with users migrating module by module. Business continuity is not at risk — critical for UK enterprises with operational SLAs and regulated uptime requirements.

By the Numbers

+ years

Powering market leaders

In-house specialists available

+ projects

Successfully delivered

% of clients

Become long-term partners

+ years

Length of our longest client partnership

Oracle ACEs

On the team, including 1 ACE Director

ISO 27001 certified · UK GDPR compliant · DORA ready · IR35-compliant engagement

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Our process

Pretius acts as a dedicated partner, not just a software vendor. We focus on delivering practical modernisation solutions that contribute to your business objectives at every stage of our engagement.

Phase 01

Analysis and ideation

Our projects begin with analysts working with you to define the problem and identify how modernisation can provide the most effective solution. We run collaborative workshops to dive deeper into your processes and goals — including your compliance obligations, talent situation, and budget constraints. When needed, we build a Proof of Concept or a working demo. We make sure we are solving the right problem, in the right way, from the very start.

Phase 02

Designing effective solutions

Once we have a clear set of requirements, our software architects and developers design a solution that meets them, provides the best business value, and fits your technology stack and long-term growth strategy. Our designers can provide clickable Figma visualisations to help you understand how the modernised system will look and work. We choose technologies purely based on what fits your project and your team.

Phase 03

Development

The actual development of the modernised solution, adapted to your preference — whether you require a fixed-scope Waterfall method, an iterative Agile process, or a combination that best fits your project governance requirements. For regulated UK organisations, we can align delivery milestones with compliance evidence requirements.

Phase 04

Maintenance

Our scale enables us to provide ongoing maintenance for the solutions we build — something many smaller UK firms cannot do. The scope of services is always clearly defined in the SLA. This commitment to long-term support is reflected in the fact that 93% of our clients continue working with us after the initial project, with some partnerships lasting over 18 years.

Phase 05

Further Scaling and improvement

Business needs change, and modernised systems must evolve to keep pace. We are prepared to extend your solution with new modules and capabilities as your organisation grows. Just tell us what you need, and we will work with you to adapt accordingly.

Flexible project approaches

01 Co-creation

Our preferred model for complex, business-critical modernisation projects. Our engineers work alongside your in-house team from day one. Knowledge transfers continuously. When the project ends, your team understands the new system deeply enough to own it — not just use it. This model was central to the T-Mobile CRM modernisation, where our developers and the client's internal team formed a single unit.

03

02 Dedicated development teams

You have a clear scope and a clear destination. We provide a cross-functional team — developers, architects, analysts, QA, DevOps, and project managers — that operates as an extension of your organisation. You maintain strategic control; we bring the execution capacity.

02

03 Comprehensive project delivery

You hand us the project, we deliver the outcome. Defined scope, defined timeline, defined budget. Minimal internal overhead for your team. Optional SLA-backed maintenance after go-live.

04 Team augmentation

When you need to quickly fill specific skill gaps within your existing team — Oracle DBA, Java, APEX, React, or PostgreSQL expertise — we provide experienced specialists to seamlessly integrate with your in-house capabilities. Fully IR35-compliant.

What our Clients say

Bilal Ramadan

CEO – Munich Re HealthTech

The solution is secure, scalable, and compatible with most technologies used by our clients. It's also much cheaper to maintain, which was an important success criteria. Application licensing costs were largely reduced.

Adam Kasperowicz

CIO – VAN group

The new e-VAN system has become an innovative tool and work environment. The development team allows us to use the potential of the latest trends and technological solutions: web & mobile development, responsiveness, integrations, low-code, and cloud computing.

Marijn van den Berg

Team Manager – Sweco

Thanks to our collaboration with Pretius, we've made it easier for our clients to utilise Obsurv. Customising the application modules to their specific needs is now much quicker and more efficient. For us, this means shorter customer onboarding times and lower costs.

Zuzanna Świętorzecka

Head of Bancassurance – BNP Paribas

The communication throughout the project was very good as Pretius provided us with a Project Manager who always addressed our needs. The most impressive thing was how quickly the team developed a fully working, market-ready software solution for us.

Artur Męcina

IT Manager – T-Mobile Poland

The most important thing about Pretius is that they care to understand your business goals. And, having a bunch of enterprise-grade and SME-grade projects under their belt, they're very good at it.

Richard Coombes

Head of Engineering – Equals Money

They allowed us to deliver against our 20/21 roadmaps, launching new products to market and increasing company revenue by over 70%.

Gordian Ratajczak

Product Owner – Neuroflash

They effectively assess a project and allocate the matching resources, which gives confidence that you are in good hands. Issues and tasks are handled proactively and communication stands on a firm ground of mutual understanding and goals. You are not hiring an external resource, but you are gaining a team member.

Marek Samujłło

CIO – Emitel

What I like the most, as CIO, is that the people at Pretius care not only about technology itself but rather about how this technology can help your company achieve business goals.

Piotr Blaszczyk

Executive Director – EBS

Pretius has a lot of experience in dealing with big, enterprise-grade companies like ours. They've proved they have a keen understanding of our needs and business goals.

FAQ

Legacy system modernisation is the process of updating or replacing outdated software applications, platforms, or infrastructure to meet current business demands and technological standards. This can involve various strategies, from re-hosting to completely rebuilding systems — the right choice depends on the business value of the existing system, its technical condition, and your organisation's strategic direction.

Modernising legacy systems helps reduce operational costs — including high maintenance fees and expensive licences for unsupported software — mitigate security risks, improve performance and scalability, enable integration with modern tools, and allow your business to adapt more quickly to market changes. For UK-regulated organisations, modernisation is increasingly a compliance imperative: operating on unsupported platforms can constitute a direct violation of FCA operational resilience requirements and DORA's ICT risk management obligations.

We offer a full range of approaches: re-hosting (moving to new infrastructure), re-platforming (migrating to a new platform with targeted improvements), refactoring (restructuring existing code), re-architecting (shifting to a new architecture), rebuilding (redesigning from scratch), and replacing (substituting with an off-the-shelf or custom solution). We can also execute combinations of these approaches across different system components simultaneously.

Our process begins with a thorough assessment of your legacy system — considering its business value, technical condition, operational costs, regulatory implications, and your long-term objectives. Based on this analysis, we collaboratively define the most suitable and cost-effective strategy. We do not recommend a more invasive approach when a lighter-touch one will achieve the same outcome.

Yes, we strongly recommend a phased approach for complex systems. This allows for incremental improvements, risk mitigation, and minimal disruption to ongoing operations. Old and new systems can run in parallel on the same underlying data during the transition, so users migrate module by module rather than facing a forced cutover. Business continuity is not at risk at any stage.

We focus on building scalable, flexible architectures using modern, widely supported technologies. Our process includes understanding your long-term business and regulatory strategy to ensure the modernised system can adapt to future growth and evolving requirements — including AI-readiness, cloud scalability, and the data governance standards that UK regulators will increasingly demand.

The timeframe and cost vary significantly depending on the complexity of the legacy system, the chosen modernisation approach, and the scope of work. After our initial assessment, we provide a detailed project plan with time and cost estimates tailored to your specific situation. For Oracle Forms projects, we use AI-assisted tooling that achieves approximately 90% accuracy on effort estimation — giving you a reliable basis for budget planning and governance approvals.

No — it makes the case for modernisation stronger, and we are experienced in designing projects around these requirements. For FCA-regulated firms, we build the modernisation roadmap so that each phase reduces rather than increases operational risk, with evidence artefacts suitable for regulatory review. For DORA-compliant deployments, the architecture is designed to satisfy DR testing, incident reporting, and third-party risk management requirements from the outset. We have delivered modernisation projects in banking, insurance, and financial services specifically under these regulatory constraints.

Yes. Every specialist is a full-time, salaried Pretius employee. By engaging Pretius Ltd — our registered UK entity — you receive a clean, risk-free B2B partnership that eliminates all IR35 off-payroll working exposure. No contractor arrangements, no hidden risk, no administrative burden.