“Softwire has been an excellent partner bringing a unique blend of technical leadership, strong engineering skills and professional management. Both projects were delivered on schedule and at a high level of quality. I have no hesitation in recommending them.”

John Palombo, Senior Vice President

The Challenge

Softwire were commissioned to develop a new voicemail, SMS and IP messaging platform for a large international provider.

Metaswitch provides a communications platform that underpins more than 1,000 networks worldwide. Its solutions are key to delivering the near-flawless communications its customers and their users – typically the general public – expect.

The platform was to be moved to a cloud-based solution which required high uptimes.  It would need to support millions of subscribers and hundreds of millions of messages each day.

Our Solution

We designed and delivered the high-availability platform and managed the entire fifteen-month programme

The high-profile, complex, multi-year programme involved working with Metaswitch’s in-house development teams and the end customer’s design team, to build and migrate to the new platform

Our remit quickly grew to a point where we were managing the full programme on Metaswitch’s behalf. This included responsibility for structuring how the work was delivered, while our Technical Director was part of the project board working directly with Metaswitch’s customer. Our architects, developers and project managers worked in and/or led combined teams at Metaswitch sites around the UK.

From a technical perspective, we designed and delivered a resilient and highly available messaging platform, capable of scaling to handle billions of messages a day. At its heart were Scala, Akka and Cassandra, the latter to enable cost-effective scaling across multiple data centres. We also engineered parts of their legacy system to ensure a seamless migration to the new system.

To deliver such a large-scale and high-profile platform required comprehensive testing; if a one-in-a-million bug were to get through, it would manifest itself many times per day once the platform was in use. We put in extensive testing infrastructure with dedicated DevOps resources combined with comprehensive automated testing.

To minimise project risk, we made knowledge-transfer a core part of the processes. This ensured that information was shared across key stakeholders.

The Result

This cloud-based platform is being rolled out to the public and achieving 99.999% uptime.

We successfully delivered the large-scale programme, which had nine separate parts over fifteen months, totalling in excess of 20,000 days’ effort. We oversaw multiple teams, with the workforce, at times, reaching almost 50 people.

Our knowledge-transfer processes successfully eliminated single points of failure and made the process of transferring knowledge back to the customer simple.

Metaswitch’s customer is rolling the platform out across its network in phases. The first parts have been successfully deployed and are achieving the required availability.


Scala, Akka, Akka Reactive Streams, Cassandra, Message Bus

The project
Large programme of work designed to support many millions of users.

The results
The first parts have been successfully deployed and are achieving the required 99.999% availability