Modern PHP vs Legacy PHP: What to Check Before Hiring

Modern PHP vs legacy PHP: not all PHP projects look alike, and understanding this difference is essential before hiring a developer. Some projects rely on modern frameworks like Laravel or Symfony, while others sit on older code, sometimes written without any framework at all and left largely untouched for years.

What is legacy PHP?

The term "legacy" refers to old code, sometimes built many years ago, without today's quality and security standards baked in. These projects may run fine day to day but become increasingly difficult to maintain and evolve, especially once the original developer is no longer around to explain their decisions.

What modern PHP brings to the table

A modern PHP project, built with Laravel or Symfony, benefits from a standardized structure, better security practices, and easier maintenance thanks to conventions widely shared across the developer community. New team members can usually get up to speed faster on this kind of codebase.

Skills to check based on your need

• For a legacy project to maintain: proven experience working with old code and the ability to quickly understand an existing project without documentation
• For a new project: solid command of a modern framework and current best practices
• In both cases: close attention to security, a critical topic on PHP projects of any age

Spotting warning signs early

During early conversations, pay attention to how a candidate talks about legacy code: dismissive comments can be a red flag if your project involves an older codebase, since a patient, methodical approach usually matters more than raw technical brilliance in that context.

Questions to ask in an interview

Ask the candidate about their experience with projects similar to yours, whether legacy or modern, and how they evaluate the state of existing code before working on it. To go further, read our complete guide to PHP, browse the PHP blog section, and check the PHP projects published on the platform.