Zen replaced traditional software with event-driven, serverless architecture.
Sector: Telecommunications
Products: Amazon Web Services
How we unlocked new business value by incrementally moving bespoke applications and on-premises infrastructure to the cloud. An approach that has enabled us to deliver on key-strategic priorities - accelerating growth, streamlining legacy systems and strengthening partner collaboration.
The Challenge
For three decades, we have operated in a highly technical, tightly regulated, ever-evolving industry. With the nationwide rollout of full fibre broadband - and independent network providers changing the market we needed to modernise quickly to stay efficient, competitive, and agile. Many of our core processes depended on bespoke, in-house software, often running on single servers in its on-premises datacentre. This setup made it harder to scale, added extra work for the team, and increased the risk of downtime. This meant that we were unable to take new orders from customers and that too much time was being spent keeping the lights on and manually deploying changes. Modernising our AWS environment allowed us to spend more time delivering the new capabilities needed by the business. As we are not a digital-native business, we needed to modernise our legacy systems step by step, rather than starting from scratch. Adding to this, regulatory changes like Ofcom’s One Touch Switch created new technical demands for providers like us, which meant we needed to quickly and reliably integrate with new systems. This needed a platform that could support both rapid change and long-term stability for our teams, our growing partner network, and our evolving customer base.
The Solution
Executive sponsorship was crucial to getting the project off the ground. John Lyons, Technology Director at Zen, explains: “Executive sponsorship was essential—not just to get the project started, but to secure buy-in across the wider leadership team. It was important for me to support our people and ensure the business had the freedom and backing needed to explore new cloud-based technologies.” That is why we adopted a serverless-first cloud strategy, building on our AWS expertise to enable incremental updates instead of a major overhaul. Developing serverless design patterns and a set of microservice blueprints meant we were able to break monolithic applications into flexible, independent components. This approach gave us the freedom to move faster and solve problems without waiting on large, risky migrations.
We applied this strategy to three major projects
Alt-Net integration To connect with Alt-Nets - the independent operators building the UK’s full fibre infrastructure - we needed reliable, scalable integration with each individual operator’s systems for onboarding and order management. To meet this challenge, we built a library of microservice blueprints: modular components that could be reused, customised, and combined as needed, allowing for new suppliers to be quickly onboarded while maintaining reliability and efficiency. With these blueprints, new supplier data uploaded to S3 now triggers automated workflows, using Amazon Simple Queue Service (SQS), Lambda, and DynamoDB to handle data processing and integration quickly and consistently.
Indirect Customer Portal Our Indirect Customer Portal (ICP) is the main tool for more than 200 partners to manage customer orders. It’s a key revenue stream, which needs to be robust, feature-rich, and ready to scale. The ICP uses the same event-driven, microservices-based approach as the Alt-Net integrations. Partners connect through APIs, and core processes like order placement, changes, billing, and notifications are each handled by modular microservices built with AWS tools including API Gateway, Lambda, Simple Notification Service (SNS), and DynamoDB.
One Touch Switch Ofcom’s One Touch Switch (OTS) rules require all providers to make switching services simple and fast for customers. That is why we needed to build a platform that could automatically sync customer data and trigger the right onboarding or offboarding workflows - under a strict regulatory timeline For this we developed two automated services: one for customers “won” and one for those “lost.” For the ‘Lost’ service, a Lambda function pulls data from an Aurora Serverless database on a schedule, stores it in S3, and sends it to a third-party OTS aggregator using another Lambda function. On the ‘Won’ service, updates to an API trigger SQS queues and Lambda functions to manage customer notifications (with Amazon Simple Email Service) and store relevant data in Aurora Serverless. This approach ensures a reliable, compliant, and fully automated switching process for both onboarding and offboarding.
The benefits
Our move to the cloud has accelerated delivery of multiple key business goals, bringing real value to the organisation:
- Scalability and security: Decoupled microservices mean systems can scale as needed while protecting critical data.
- Lower overhead and cost control: Automation and efficient design reduce operational effort and help us keep costs manageable while growing.
- Faster delivery: Repeatable blueprints speed up onboarding, feature releases, and regulatory projects - helping us respond to a changing market.
- Reliable service: Standardised solutions mean customers and partners get a consistent, dependable experience.
- Ready for what’s next: With a cloud-native platform, we can focus on new priorities, adapt to fresh business needs, and keep pace with industry changes. By moving to serverless, cloud-based architecture with AWS, we are now set for continued agility and growth - even as the industry evolves.
