Big Migration: From 2,200 Sites to One Unified Platform

By migrating member association microsites to a stable, multi-tenant Drupal platform, Bostadsrätterna, Sweden's largest condominium association, simplified the management of its entire web network and reduced hosting costs by 50%.
 

Bostadsrätterna is a dynamic organization that continuously develops and offers new services to its members. Currently, more than 2,200 condominiums use the association's service "Own Website," and this number keeps growing. 

Interested in increasing the number of customers, the organization recognized the need to change its approach to website management. It was looking for a way to ensure security, streamline the maintenance, and simplify platform scaling.

The key issues were:

• Outdated platform and rising costs. Bostadsrätterna was running the member microsites on a legacy Drupal 7 platform with the Aegir hosting system. While this setup had served its purpose in the past, it had become expensive and increasingly difficult to maintain. The fragmented infrastructure drove up hosting and support costs, while the aging technology limited flexibility for future growth.
• Slow deployments and security risks. Managing thousands of sites in parallel created major operational problems. Deployments were slow and often unstable. On top of that, Drupal 7 was reaching end-of-life. Without further community support, the platform would no longer receive security updates, putting a large network of sites at risk.
• Scaling and onboarding limitations. Creating and launching new sites was complicated and time-consuming, which slowed down onboarding and made it hard for the organization to expand its network at the pace it had the potential for.

For almost a year, in collaboration with the Swedish IT company NORXSYS, the Jet.Dev team has been maintaining Bostadsratterrna’s microsites. Confident in our reliability as partners, the organization decided to undertake a major project to migrate domains to a new platform together.

Our primary goals included:

• Migrate 2200 sites from Aegir to one multi-tenant platform.
• Upgrade Drupal from 7 to 9.
• Guarantee data security, avoid data mixing, and limit users' access to one assigned domain.
• Modernise UI, while leaving it familiar and convenient to users.
• Add a new custom theme and the ability to switch between themes.

• Implement a tool for quick and easy new site creation.

   

Before starting full migration, we launched a Proof-of-Concept (PoC) to validate the architecture, test assumptions, and minimize risk. A successful PoC reassured stakeholders and confirmed we were ready to scale.

Phased Migration with Minimal Downtime

Migrating 2,200 websites required a careful balance between speed and stability. A full, simultaneous migration would have resulted in extensive downtime - up to a full week in maintenance mode. 

Instead of taking the entire platform offline, we designed a phased migration approach that kept services available throughout the project:

• Sites were grouped into batches of 200 and migrated during low-traffic periods to minimize impact on members and administrators.
• Automated CI/CD pipelines handled deployments safely and consistently, reducing the risk of human error.

• Continuous monitoring and controlled rollbacks ensured any issues could be resolved immediately, keeping the platform stable at all times.

   

This strategy allowed Bostadsrätterna to move to the new platform without stress for the IT team and for end users. 

Unified Multi-Tenancy with Security and Control

To give Bostadsrätterna a stable and scalable foundation, we implemented a customized multi-tenant architecture on Drupal. This made it possible to manage thousands of microsites as one while keeping them secure and flexible for individual editors.

It was provided: 

• Secure isolation: Each microsite is fully separated, protecting data and reducing compliance risks.
• Centralized control: Administrators can manage thousands of domains from one interface, dramatically simplifying oversight and reducing effort.
• Scoped access: Editors only see and manage the domains assigned to them, ensuring clarity and security across the network.

Enhanced Performance with Smarter Search

The default Drupal search was replaced with Apache Solr, reducing database load and ensuring fast, reliable search performance even as the network continues to grow. This upgrade not only improved the user experience but also strengthened the platform’s ability to scale without performance issues.

Preparation for the Big Migration took about three months. However, the results obtained from the project implementation definitely worth the time invested:

At Jet.Dev, we work with our clients to build reliable, lasting partnerships. This approach allows us to understand partners' goals deeply and not only deliver technical solutions, but also help to achieve business objectives, implement ambitious plans, and get measurable results.

If you are looking for a reliable partner to support your digital growth, let’s start a conversation.