Switch2 is the UK's most experienced provider of end-to-end solutions for heat networks. The business partners with local authorities, housing associations, and private developers to optimise energy efficiency, manage renewable energy, and minimise costs for residents. If you've watched a legacy platform that's been the heart of the business for two decades start to limit what the next decade can do, you'll recognise the position Switch2 had reached.
Switch2 operated its core systems on-premises, which had become challenging to maintain and scale. The technology stack was built on programming languages and architectural patterns nearly two decades old. A critical issue was the reliance on legacy batch processing, where data from tens of thousands of meter points created a "spiky" load pattern that was inefficiently handled by an overnight batch job.
The legacy environment meant the in-house team was constrained, spending its time on maintenance rather than innovation. The rigid systems were inefficient, costly, and a significant barrier to launching new products and services.
Switch2 partnered with D55 for a collaborative migration and modernisation project on AWS. This wasn't a technical handover; it was a joint build focused on upskilling. D55 engineers worked alongside Switch2's developers, introducing them to modern cloud-native patterns and engineering practices.
The core platform was fundamentally re-architected from a slow batch process into a modern, asynchronous, event-driven model. Core services were containerised using Amazon ECS, transforming the system from one that processed data overnight to one that could react to events in real time.
The first event-driven flow released into production without the overnight wait. The Switch2 team saw their own platform respond in real time to a meter-point change, and the conversation shifted from "when will the batch finish" to "what can we build next".
Elimination of legacy bottlenecks. The modernised platform scales on demand, improving reliability and efficiency while reducing the total cost of ownership.
An empowered in-house team. Switch2's internal development team now has modern cloud skills. The team has shifted from a reactive maintenance mindset to proactively building new, innovative services on a platform it controls.
Accelerated speed-to-market and a future-ready platform positioned for AI for future optimisation.
"D55 are a highly experienced team that helped lead our business to push for and deliver an innovative and ambitious legacy to AWS transformation, with confidence. D55 have become a valued development and consultancy partner thanks to their excellent practical capability and their ability to apply the most appropriate working methodology to the challenge at hand."
Ed Berry, Head of Digital Products, Switch2
The pattern transfers. When your legacy on-premises platform sits on architectural decisions made a decade or two ago, and your in-house team is the team your business needs for the next phase, the right move is rarely lift-and-shift and rarely a multi-month rewrite. A joint upskilling build, sequenced as releasable chunks on AWS, lets your engineering team continue to ship while the architecture changes underneath them, and leaves your team owning the platform afterwards.
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