According to the “State of digital government review”, published in January 2025, an estimated 28% of systems in 2024’s central government depend on decades-old legacy technology that’s unsupported and has maintenance costs often 3 to 4 times more expensive than modern alternatives.
It’s why digital transformation often stalls. Large, monolithic systems that are complex, rigid, and vendor‑locked are barriers to change, and harder and more expensive to secure, which in turn, introduces operational and cybersecurity risks. End-of-life tech not only constrains agility, slow decision‑making and inflate costs, but blocks the adoption of more advanced technology, like AI. Outdated systems, poor-quality data, and fragmentation make it difficult to leverage data well or smoothly integrate new solutions.
The legacy challenge in justice
The Justice and Security space is a high-stakes legacy problem that’s about more than just cost. Legacy system failures or breaches poses an operational and national security, given the sensitivity of justice and security data like criminal records, intelligence, legal case data.
Which is why agencies should consider pivoting toward modular, interoperable, and scalable architectures to deliver real transformation. In its Digital Strategy 2025, for example, the Ministry of Justice states it wants to reduce reliance on legacy systems, move more services to Cloud, and unlock data from their monolithic legacy systems to allow better integration and modern tooling. Many of these core systems were designed decades ago. They were never intended to integrate with modern cloud environments or support real‑time data. The result is siloed information, duplicated effort and complex workarounds with endless off system working. This is particularly problematic in security, where siloed data limits the ability to do joined-up analytics, intelligence-sharing, and proactive prevention.
Replacing these systems wholesale is often seen as too risky — but incremental modernisation offers a path forward.
Modularity and agility
Microservices, APIs and cloud‑native platforms enable departments to build capability step by step. Instead of one monolithic programme, smaller components can be developed, tested and deployed independently. This approach supports agile working, continuous improvement, faster innovation and better resilience, which is critical for justice, border and security systems that must operate 24/7. By decoupling core functions, teams can modernise high-risk legacy areas without taking entire services offline, and new capabilities—such as identity verification, risk scoring or case-management workflows—can be introduced incrementally.
In the justice and security space, this is particularly important, as systems often span multiple agencies with differing data standards and operational pressures. Moving toward API-first integration allows information to flow more reliably between courts, prisons, police forces and border operations, reducing manual workarounds and data silos.
What good looks like
Good architecture enables flexibility. It aligns technical design with operational outcomes, reduces duplication, and makes integration easier across agencies. Most importantly, it allows AI, automation and data analytics to be layered on top, driving smarter and faster services without wholesale replacement of legacy systems. These components can be isolated, wrapped or gradually replaced, rather than rewritten in one high-risk leap. Over time, this creates a more adaptable and flexible digital estate—one that can evolve with changing policy, threat landscapes and user expectations without requiring another generation of monoliths.
Ultimately, “good” isn’t defined by one single technology choice, but by whether systems can evolve safely and predictably over time. A modern estate is one where critical services are modular enough to change without jeopardising operational continuity, where data flows smoothly across organisational boundaries, and where teams have the oversight and automation needed to detect issues early and recover quickly.
Transformation isn’t about tearing everything down. It’s about evolving what exists, piece by piece, toward a more adaptable, secure and user‑centred environment. It’s also about ensuring you bring your people with you as the culture shifts alongside technological changes, as explored in this piece.
In Transform’s experience, the organisations who succeed are those that balance ambition with pragmatism — moving beyond monoliths without losing momentum.
If you want to explore how we can help your department move from monolithic legacy systems to an integrated, modern estate, get in touch today.