In 2017, John Lewis, a leading UK retailer, confronted the challenges of its aging monolithic e-commerce platform. Hampered by sluggish release cycles and complex cross-team dependencies, the organization recognized an urgent need for transformation. The answer lay in empowering developers and modernizing its digital infrastructure to meet rapidly changing business demands.
Leveraging Google Cloud and Kubernetes for Agility
John Lewis began its modernization journey by migrating the e-commerce frontend to Google Kubernetes Engine (GKE) on Google Cloud. This strategic shift immediately accelerated release cycles from monthly to weekly, proving the value of cloud-native architecture. The success of this move motivated the company to extend cloud adoption across additional business areas, guided by a platform engineering mindset that emphasized autonomy and speed.
Redefining Teams with Platform Engineering Principles
The transformation aimed to build a modern digital platform where product teams could independently develop, deploy, and manage microservices. Adopting the mantra, “You Build It. You Run It. You Own It,” John Lewis decentralized both development and operations, fueling scalability and innovation across its technology landscape.
Embracing Multi-Tenant Architecture
A pivotal element of this transformation was the adoption of a multi-tenant architecture. Each business service became a distinct tenant, granting teams independence and reducing interdependencies. Services, defined as logical business applications of microservices and data, remain central to the company’s ability to scale and adapt today.
Teams were encouraged to “bring your own container” or use native Google Cloud services such as Firestore and Pub/Sub. This balance reduced complexity in areas like resilience and disaster recovery, while Kubernetes ensured teams had the autonomy they needed without sacrificing platform governance.
Autonomy with Guardrails: The Developer Pathway
Product teams gained control over their own namespaces and projects, giving them freedom to build and iterate rapidly. Early adopters, such as the team rebuilding johnlewis.com search, helped evolve the platform by providing feedback and embracing Google Cloud-native capabilities.
Introducing the Paved Road for Developer Success
To avoid the pitfalls of unchecked autonomy, John Lewis introduced the “paved road”—a curated set of standards and automation for safe, efficient development. This initiative brought:
- Standardized platform features for rapid delivery
- Consistent practices across teams, facilitating easy knowledge sharing and mobility
- Assurance that best practices were followed through built-in capabilities rather than strict controls
Key paved road features included:
- Paved Road Pipeline: Automates Google Cloud resource provisioning and observability via a YAML-based Service Definition.
- Microservice CRD: (Detailed in part two) Simplifies Kubernetes management with microservice-level abstractions.
Simplifying Operations and Reducing Developer Overhead
The Service Definition empowers teams to specify their requirements in a simple configuration, which triggers CI/CD pipelines for automatic provisioning and operations. Platform-owned “provisioners” handle tasks like bucket creation, Pub/Sub setup, dashboard configuration, and SLO alerting. This abstraction allows developers to focus on delivering business value instead of dealing with complex infrastructure.
With this approach, the platform team can more efficiently add features and maintain consistency. Widely adopted tools like Pub/Sub become defaults, streamlining everything from resilience to security and incident response.
Balancing Innovation with Consistency
The paved road isn’t mandatory—teams can explore the “dusty path” to experiment or the “crazy paving” for unique needs. If a non-standard solution gains traction, the platform team works to make it a self-service option. This structure fuels innovation while maintaining a foundation of best practices and standardization.
A Future-Ready Platform
John Lewis’s journey showcases how adopting multi-tenant architecture and a developer-focused paved road can transform the developer experience. Through automation, clear guardrails, and a culture of innovation, the company has accelerated development, empowered its teams, and created a robust, adaptable technology platform. This approach positions John Lewis to thrive as technology and business requirements evolve.
To learn more about the Microservice CRD and its impact, visit part two of the series.
Source: Google Cloud Blog
How John Lewis Revolutionized Developer Experience with Platform Engineering