Drupal Upgrade Without Stress: How to Migrate Without Losing Money and Time

An online retailer with substantial annual turnover decided to upgrade their site on their own. The result? Two weeks of downtime, nearly half of their sales lost, and incorrect data in the product catalog. The main mistake — lack of a backup plan and preliminary testing.

An international company entrusted their Drupal upgrade to an inexperienced contractor. During migration, they lost three years of content history, broke CRM system integration, and lost all SEO settings. Recovery cost the company additional expenses and a 2-month delay.

An educational platform faced complete incompatibility of critical modules after upgrading. The result — unstable operation, user loss, and reputational damage. The technical team didn't account for the architectural changes in the new Drupal version.

When others limit themselves to a surface scan of the code, we conduct a two-phase audit. First, we analyze the visible part: modules, configurations, custom code. Then we dig deeper – checking the "archaeological layers" of the project where non-obvious dependencies hide.

Recently, for a large commercial company, we found a custom module forgotten by everyone, which was added to the code 5 years ago and wasn't displayed in the admin panel. Discovering it before migration helped avoid serious problems with business processes.

We don't upgrade the existing site "blindly" – we create a full copy in the test environment. We apply this technique for high-traffic sites where every minute of downtime matters.

For an e-commerce client from Germany, we managed to significantly reduce the transition time to the new version – simply because we identified and resolved most issues in advance in the test environment.

Instead of a simple upgrade on the production server, we apply a carefully thought-out process. We first conduct full testing in a separate environment, identify and fix all issues, and then perform a controlled transition with a detailed rollback plan.

In our practice, there was a case where a client could quickly return to the previous version after detecting an issue – because we developed a step-by-step rollback plan with clear actions for each stage. Most teams neglect this, hoping for a successful upgrade.

When standard migration modules can't handle complex data, we write custom scripts. For a university portal with 25,000 pages and non-standard taxonomy, we developed a special approach that preserved all relationships between entities.

Modern Drupal is a real technological leap compared to previous versions. Our team, working with dozens of upgrades, has identified key aspects that critically impact migration success.

Modern Drupal is built on a component architecture with the Symfony framework at its core. This provides extraordinary flexibility but requires a special approach to migration. When upgrading, you have to rebuild not only modules but rethink the entire business logic of the site.

In practice, we encounter problems transferring custom hooks – one of our clients had over 200 hooks in custom.module, which in modern Drupal had to be rewritten as separate services or plugins. Failing to consider this aspect often leads to "dead" functionality on the upgraded site.

Modern Drupal uses a completely different routing and access control system. Instead of simple permissions, it now applies a more complex but reliable Access Control system where each entity can have its own rules.

For corporate clients with multi-level access, this means completely rewriting authorization rules. In a recent migration project, we created a special tool for automatic transfer and testing of access rights, saving weeks of manual work.

For sites requiring modern UX, understanding how modern Drupal supports JavaScript frameworks is critical. Instead of traditional libraries, a webpack-based asset system has been implemented, and REST and JSON

modules have become part of the core.

We've confirmed that in modern Drupal, you can seamlessly integrate React components even without moving to a fully decoupled approach. For a corporate portal, we implemented a "hybrid" architecture where some pages are generated traditionally, and user experience-critical elements are handled through React.

One of the most common problems is transferring media files and images. Modern Drupal introduced a completely new Media entity that replaces old file fields. During migration, you need to not only transfer the files themselves but rebuild the entire system of their storage, use, and display.

To migrate 50,000+ images from a multi-year news portal, we created special field translators and migration processors that preserved all connections between content and media files.

The question that often arises for Drupal site owners is: "Maybe it's better to simply switch to WordPress or another platform instead of upgrading?" The answer isn't as straightforward as it might seem.

Drupal was and remains the best solution for complex, high-load sites with non-standard business logic. Modern Drupal has maintained its architectural advantage over WordPress and other CMS in terms of scalability and security.

For one of our clients – a media portal with over 500,000 unique visitors daily – we conducted a comparative analysis of migrating to WordPress versus upgrading Drupal. The result? WordPress simply couldn't provide the needed flexibility for complex taxonomy and user profile management.

Upgrading Drupal isn't just about maintaining the current version. It's an opportunity to implement modern technologies to solve business challenges:

Flexible API system for integration with mobile applications and third-party services 

Built-in GraphQL support for complex data relationships 

Caching system with invalidation control that can withstand peak loads Improved 

Paragraphs approach for flexible content management

Cost analysis for our clients shows that the cost of completely rebuilding a site on another platform is usually 40-70% higher than upgrading Drupal. Besides direct costs, consider:

Preserving the site's established SEO profile 

No need to retrain content editors

Possibility of phased implementation of new functionality 

Significantly shorter project implementation time

A medical portal after upgrading to modern Drupal improved its search rankings for target queries, which brought an increase in organic traffic. An online store gained the ability to manage the catalog via API, allowing integration of a single product database with offline stores.