Overcoming legacy IT: Modernising through, not around, existing systems
Public sector organisations face a growing transformation challenge. While investment in new technologies continues to increase, many departments remain constrained by complex legacy estates that consume the majority of technology budgets, limit agility and make innovation difficult.
The problem is often framed as one of technology replacement, but this overlooks a more fundamental reality. Most legacy systems continue to perform critical functions that organisations rely on every day. Attempting wholesale replacement can be expensive, disruptive and high risk. The question is not simply how government replaces legacy technology, but how it extracts greater value from it while creating a path to future innovation.
Industry has an important role to play in helping government move beyond what could be described as the "97% problem", where resources are focused on maintaining existing systems, leaving limited capacity to innovate. Effective transformation begins with understanding the legacy estate itself: identifying business-critical processes, mapping dependencies and assessing where modernisation can deliver the greatest operational benefit.
This requires a shift away from large-scale replacement programmes towards incremental, outcome-driven modernisation. By introducing modern integration layers, improving data accessibility, automating manual processes and modernising services iteratively, organisations can reduce risk while delivering tangible benefits more quickly. In many cases, the most successful transformations are achieved not by working around legacy technology, but by modernising through it.
This approach is becoming even more important as public sector organisations seek to adopt AI. The potential benefits are significant, from improving citizen services and reducing administrative burden to supporting better operational decision-making. However, AI cannot compensate for poor data quality, fragmented systems or weak technology foundations.
The effectiveness of any AI solution depends on the quality, accessibility and governance of the data that underpins it. Where information is fragmented across disconnected legacy systems, organisations risk creating additional complexity rather than generating value. Before AI can transform public services, government must address the foundational challenges of data, architecture, governance and interoperability.
This is where industry expertise is most valuable. Technology partners can help organisations develop realistic modernisation strategies, establish trusted digital foundations and prioritise investments that deliver both immediate operational improvements and long-term transformation outcomes. Successful modernisation combines technical expertise with a deep understanding of organisational change, risk management and service delivery.
The goal should not be to eliminate every legacy system. Instead, it should be to create a technology environment in which legacy and modern platforms work together effectively, enabling organisations to innovate with confidence while maintaining the resilience and reliability that public services demand.
As government seeks to deliver smarter, more efficient and more responsive public services, overcoming legacy IT will depend less on wholesale replacement and more on adopting pragmatic, sustainable approaches to modernisation. By helping organisations modernise through legacy technology, strengthen data foundations and prepare for emerging technologies such as AI, industry can play a pivotal role in unlocking the next generation of public sector transformation.
