A UK household name and one of the world’s largest mutual financial institutions, our client has over 14 million members and a history that stretches back more than 170 years. Over time, this financial institution has developed many systems to accommodate the various financial services it provides for its customers.
What was the problem?
They came to us with several different legacy platforms that had been built up over many years. This made new developments time-consuming and expensive, and therefore put the business at a competitive disadvantage.
The requirement was to modernise their payment systems via a new platform on the cloud, with a design that was future-proofed as much as possible to allow the business to provide financial services in keeping with the expectations of today’s banking customers.
Our client’s preference is to buy and integrate a payment processing product from a fintech vendor. As part of the contingency planning, our client needed to understand the alternative: ground-up development of a new platform in case a suitable product could not be procured and configured.
Owing to 345 Technology’s long experience of banking payments and our expertise in building cloud solutions, we were engaged to perform a detailed architectural analysis of the current platforms and what a future platform might look like.
What did we do?
We began the project by analysing the legacy platforms, to understand the makeup of the systems that would need to be replaced. We categorised these into a hierarchy, from platform down to system down to subsystem.
We then needed to identify dependencies throughout the platform. This meant assessing relationships between components, databases, services and technologies, as well as understanding how these relationships would affect the infrastructure and deployment plans.
For each element of the platform, we assessed its size and determined the relevant technology stack. We could then analyse the functional capabilities supported by each component.
We listed all functional capabilities needed for the new platform. Just as we categorised the legacy setup by platform, system and subsystem, we did the same for the target state of the new setup.
We created a candidate cloud architecture based on microservices – small, autonomous units that could be reused across different parts of the new cloud setup.
For each part of the new setup, we noted:
- Microservice type
- Technology mix (type of database, queuing system, how we store files)
- Functional capabilities supported
This led to us reducing the legacy setup’s 7 platforms into a design built with 76 microservices but comprising only 4 main areas:
- External connectivity to other banks
- Internal connectivity to ledgers and other systems of record
- APIs, services & business logic
- Workflows
How is this delivered?
With all this work done, we were able to define our intended design for the future state of the system, based on a 5-year roadmap.
This future state would be reached only after passing the following transition states:
- Transition state 1: demonstrating a viable working architecture and the minimum scope to demonstrate proof of value in the new design.
- Transition state 2: delivering the most value and best performance as quickly as possible, focusing on the biggest wins first.
- Transition state 3: moving through the next high-value tasks and speeding up the rate of progress.
- Transition state 4: completing the lower-value tasks at an even faster rate.
- Transition state 5: cleaning up and closing down the legacy systems.
What was the result?
We delivered a completed design that gave them a clear 5-year roadmap for implementation, to minimise risk and maximise value delivery.
The key benefits of the design we delivered (if implemented as recommended) are:
- An “always-on” platform that serves customers even during upgrades.
- A reduction in operating costs by flexing cloud resources with demand.
- An increased ability to respond to market change faster and cheaper.

Executing our design would deliver:
- 4 new platforms to replace the existing 7.
- A cloud-based workflow using scalable modern technologies such as Apache Kafka and Kubernetes.
- 76 new microservices and workflows.
- Retirement of 100s of on-premises servers.
What's next?
The story doesn’t stop there! This programme of modernisation is important and 345 Technology are continuing to help our client on their journey to deliver world-class systems designed to meet all the demands of modern finance.