Enterprise App Modernisation & Legacy Migration Services


We modernise legacy systems and deliver secure, scalable integrations that make enterprise platforms work together seamlessly.



ISO 27001 certified and trusted by government and enterprise at scale.

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Strategic Legacy System Migration


Modernising applications isn’t always about starting from scratch. Legacy systems often contain valuable business logic and proven processes. Our approach balances innovation with pragmatism — selecting the right strategy to modernise while protecting existing value and reducing risk.

RE-PLATFORM & RE-ARCHITECT

We migrate apps onto modern platforms and redesign underlying structures for performance, scalability, and cloud-native benefits — without a full rebuild.

REFACTOR & OPTIMISE

We improve existing code, frameworks, and libraries to enhance efficiency, security, and maintainability — giving legacy apps a new lease on life.

REDESIGN, REBUILD, REPLACE

When incremental steps aren’t enough, we deliver full redesigns or replacements — building modern, user-centric applications that align to enterprise goals.

Our Modernisation Tech Stack


We’re platform-agnostic — choosing the right technology to meet your requirements for performance, security, and scalability. Our teams deliver across the leading frameworks, cloud platforms, and integration technologies used in enterprise environments.


→  Front-End Frameworks -  React, Angular, Vue, Blazor

  Back-End & APIs -  .NET, Java, Node.js, Python, PHP

  Cloud & Infrastructure -  AWS, Azure, GCP, Kubernetes

  Integration & Data - REST, GraphQL, Kafka, MuleSoft

  Security & Standards -  ISO 27001, DevSecOps, WCAG

Recent Projects


From reporting platforms to portals, we deliver enterprise systems that serve hundreds of thousands of users securely at scale.

MICROSERVICES RE-ARCHITECTURE

We re-architected a microservices solution within a large enterprise program of work after the existing system failed to scale. Built on Kafka with bounded contexts and ACLs, the new architecture ingests telemetry from ~100,000 constantly streaming devices, delivering resilience and performance at scale.

PORTAL MODERNISATION

We engineered a major upgrade to a business-critical education application, migrating from an older .NET version to .NET 7 and shifting the UI from AngularJS to React. These changes halved CPU usage, enabled cross-platform capability, and roughly doubled development velocity through modern frameworks and hot-reloading.

APP RE-PLATFORM

We delivered four apps across iOS and Android as part of a re-platform modernisation. The current team were upgrading from Xamarin to Maui with little success. Our recommendation was to rebuild using AI augmentation for React Native. This resulted in delivering the MVP for the apps in just two weeks.

FAQs


  • What is the difference between re-platforming and refactoring?

    Re-platforming moves your application to the cloud with minimal changes, while refactoring optimises the code to take full advantage of cloud-native features like scalability and cost-savings.

  • Do you handle legacy data migration?

    Yes. We specialise in complex data migration from on-premise legacy databases to modern cloud data warehouses, ensuring data integrity and security throughout the process.

  • How do you ensure business continuity during a system migration?

    We minimise risk by using strategies like the 'Strangler Fig' pattern, where we gradually replace specific functions of the legacy system with new microservices while the old system keeps running. This allows for incremental releases with zero downtime and ensures your business operations are never interrupted.

  • Should we rebuild our legacy application from scratch or modernise it?

    Not every app needs a full rewrite. We start with a technical audit to assess your code quality and business goals. If the core logic is sound, we recommend re-platforming or refactoring to save time and budget. We generally only recommend a full 'greenfield' rebuild if the existing technology is obsolete or inhibiting business growth.

  • Do you offer a code audit or assessment for existing legacy systems?

    Yes. We offer a structured Discovery & Audit engagement where our architects review your current codebase, infrastructure, and security posture. You receive a detailed roadmap and technical recommendation report, which you can use to validate your modernisation strategy before development begins.

Latest Blogs


Patient Zero named triple finalist at ARN Innovation Awards 2025 for Technical Excellence, Marketing
October 27, 2025
Patient Zero named finalist in three categories at ARN Innovation Awards 2025: Technical Excellence, Marketing Excellence, and Enterprise Innovation. Learn more.
By Hanieh Madad September 29, 2025
At Gartner Gold Coast 2025, everything was about AI — automation, efficiency, disruption, predictions. AI, AI, AI. But in between all that noise, I found myself thinking about how I work, and how I’ve found working at Patient Zero. Some of the things they talked about, like trust, autonomy and team culture, are the things I’ve experienced here.
By Joe Cooney September 25, 2025
The Joy of Faking It - Reducing Security Risks in Legacy System Enhancement with Synthetic Data
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