Reusability Audits: How To Decide What To Reuse, Refactor, Or Rebuild In Drupal Migrations

Introduction

In Drupal migrations, it’s tempting for executives to assume that the existing platform can simply be “lifted and shifted” for a new brand or site. The logic sounds simple: reuse what’s already there, and the project will move faster and cheaper.

But not all code is created equal. Some components are modular, well-documented, and reusable. Others are tightly coupled to old business logic, fragile, or poorly maintained. Blindly reusing everything risks carrying forward technical debt. On the other hand, rebuilding everything from scratch wastes time, money, and proven functionality.

The answer lies in a structured reusability audit: a systematic assessment that reveals what to reuse, what to refactor, and what to rebuild, giving leaders clarity and governance in their migration strategy.

The Problem: Blind Reuse Vs. Smart Reuse

Two extremes often derail migration projects:

Over-reuse Without Validation

• • Developers often carry forward modules and components, assuming they “worked fine before, so they’ll work again.” But these modules may contain hardcoded values such as UUIDs, taxonomy terms, or environment-specific IDs that immediately break in a new setup.

• • Site Studio components, helpers, or layouts may have been designed with a single brand in mind. For example, a “Race Highlights” helper tied to one brand’s taxonomy becomes useless for another.

• • Themes built with CSS overrides and patch fixes create brittle front-ends that fail when new templates or branding are introduced.

• • Poor or missing documentation forces new teams to reverse-engineer functionality, adding hidden costs.

• • The result: what looked like a “time saver” ends up increasing debugging and refactoring costs mid-project.

Over-rebuilding Out Of Fear

• • To avoid carrying risks forward, some teams adopt a “rebuild everything” mindset. This often leads to reinventing proven functionality such as user authentication, event listing modules, or search filters.

• • While this feels safe, it extends timelines and inflates budgets unnecessarily, consuming resources that could be invested in innovation.

• • Rebuilding also introduces risk of new bugs in features that had already been validated in production.

• • The result: “safety” comes at the expense of efficiency and velocity.

Executives need evidence, not assumptions. A structured audit prevents both extremes, offering a balanced view of what should truly be reused, adapted, or rebuilt.

A Structured Reusability Audit

To solve this, Axelerant developed a standardized audit template, ensuring consistency and rigor across migrations. The audit divided responsibilities between front-end and back-end teams, covering every layer of the platform.

Here’s what the audit looked at in depth:

Modularity & Encapsulation

• • Are modules written as self-contained units with clear inputs and outputs?

• • Can they be ported to a new site without hidden dependencies?

• • Example: A content carousel coded as a generic block is reusable. A carousel tied to a specific taxonomy vocabulary is not.

Code Quality & Best Practices

• • Does the code follow Drupal and PHP coding standards (naming conventions, indentation, PSR compliance)?

• • Are there signs of code duplication or “copy-paste” reuse, which create future maintenance challenges?

• • Does the architecture follow SOLID principles, making it easier to extend or maintain?

Parameterization & Configuration

• • Are values like taxonomy terms, UUIDs, or block IDs hardcoded, or are they abstracted through configuration?

• • Can modules accept different parameters for different brands without changing the code?

• • Example: A “Featured News” block that pulls articles by configurable taxonomy term is reusable. If it’s hardcoded to “Sports,” it’s not.
    
    

• • What external libraries or contrib modules does the code rely on? Are they actively maintained?

• • Are there dependencies on deprecated APIs that will break in the next Drupal upgrade?

• • Do custom modules unnecessarily duplicate functionality already available in contrib?

Site Studio Components

• • Are components generic enough to be reused across multiple brands?

• • Do editors have clear documentation for how to use them?

• • Is there redundancy in helpers (e.g., three slightly different “Hero Banner” helpers, none standardized)?

• • Can styles and branding be easily overridden per site, or are they hardwired to one brand identity?

Theming & Front-End Architecture

• • Is the theme modular and atomic (e.g., leveraging Twig templates, reusable design tokens)?

• • Or is it reliant on nested CSS overrides and legacy classes, which cause conflicts when scaling to new sites?

• • Are assets optimized (minified CSS/JS, lazy-loaded images) for performance?

Documentation & Testing

• • Does the codebase include inline documentation, README files, or architecture diagrams?

• • Are there unit tests, Behat tests, or CI/CD pipelines ensuring reliability?

• • Without these, reuse becomes high-risk since functionality can’t be validated quickly.

Performance & Scalability

• • Are caching strategies in place (Drupal cache API, CDN integration)?

• • Are database queries optimized, or do they involve nested loops and inefficiencies?

• • Can the code handle higher traffic loads without redesign?

Each component was evaluated, scored, and mapped to one of three categories: Reuse as-is, Refactor, or Rebuild.

Comparison Table: Reuse Vs. Refactor Vs. Rebuild

The Outcome: From Guesswork to Governance

The audit delivered more than a checklist, it provided a decision framework that transformed uncertainty into confidence:

• Identified truly reusable modules and components, ready for direct adoption.
• Flagged high-value features that required refactoring, saving time compared to rebuilding, while removing risks.
• Exposed fragile or outdated code that should be rebuilt to avoid carrying technical debt.
• Produced a standardized audit template for future migrations, reducing ramp-up time in subsequent projects.
• Enabled executives to make evidence-based decisions, balancing speed with sustainability.

This shifted the migration approach from “assumption-driven reuse” to governance-driven reuse.

Lessons for Executives

• Not all reuse is created equal. Reusing poor-quality code introduces liabilities that will cost more later.
• Evidence is power. Structured audits remove subjectivity and help executives allocate effort strategically.
• Governance begins with reusability. Consistent components and documented patterns ensure scalability across multiple brands and regions.
• The middle ground matters. Refactoring is often the optimal choice, balancing cost savings with quality improvements.
• Frameworks compound value. The audit process itself becomes an asset, reusable for every future migration and upgrade.

Reuse With Confidence, Not Assumptions

In Drupal migrations, speed pressures can push organizations toward risky shortcuts (“reuse everything”) or wasteful overhauls (“rebuild it all”). Both extremes drain resources and erode confidence.

A structured reusability audit ensures you can make informed decisions about what to reuse, refactor, and rebuild. The result: faster delivery, reduced risk, and a scalable foundation for future growth.

If your organization is considering a Drupal migration, Axelerant can help audit your platform for reusability, so you can accelerate delivery without inheriting technical debt