Custom PHP development services for core PHP and legacy applications

A lot of working business software is plain PHP. It was written years ago by a developer who has moved on, it runs the orders or the bookings every day, and nobody wants to touch it. Custom PHP development services exist for exactly this: careful work inside an application that cannot be switched off.

Core PHP is also a sensible choice for some new work. A single-purpose tool, a webhook receiver, a data import script, a scraper or automation script run by cron, or a small form on shared hosting does not need a full framework. With Composer, PDO and PHP 8's type system, a few hundred lines of plain PHP can be clean, tested and easy to hand over.

Where I will steer you elsewhere: a new application with user roles, many screens and business rules should be built on a framework, because routing, validation, authentication and queues come solved and tested. For that, see my Laravel development services. I will tell you honestly which side of that line your project falls on.

Legacy PHP development is mostly about not causing damage. Code written for PHP 5.6 or 7.x often breaks in ways that are quiet rather than loud, so I look for the specific changes that catch old applications out:

• Removed functions. The mysql_* extension was removed in PHP 7.0, and each() and create_function() were removed in PHP 8.0. Old code that still calls them stops with a fatal error.
• Changed comparisons. Since PHP 8.0, comparing a number with a non-numeric string compares them as strings, so 0 == "abc" is now false. Login checks and status flags that relied on the old behavior can change meaning without any error.
• Null passed to built-in functions. From PHP 8.1, passing null to parameters such as strlen() or trim() raises deprecation notices, which fill logs and hide real errors.
• Dynamic properties. PHP 8.2 deprecated creating properties that a class never declared, a pattern common in older models and libraries.
• Unsupported versions. PHP 7.4 stopped receiving security fixes in 2022 and PHP 8.1 at the end of 2025. Staying on them leaves known vulnerabilities open.

Before changing anything, I get a copy running locally against a sanitized copy of the database, turn on full error logging, and write down how the main flows actually work. On code without tests, I add a few characterization tests around the parts I am about to touch, so any change in behavior shows up immediately.

Static analysis does much of the searching for me: PHPStan and PHP_CodeSniffer with the PHPCompatibility rules list problem lines by PHP version, and Rector can apply the mechanical fixes. The judgment calls, such as what a loose comparison was supposed to mean, I make by hand and note in the pull request. If you need a full version move, my PHP 8 upgrade service covers it end to end, and the PHP 8 upgrade checklist shows the steps.

Security gets the same attention. Custom PHP has none of the protection a framework adds by default, so I check for:

• SQL built by joining strings, replaced with PDO prepared statements
• md5 or sha1 passwords, moved to password_hash() and password_verify() with a rehash on next login
• Forms without CSRF tokens, and output printed without htmlspecialchars()
• Sessions not regenerated after login, and cookies without the HttpOnly, Secure and SameSite flags
• File uploads checked only by extension, or stored inside the public web root

Companies that hire PHP developers in India usually want one of two things: a freelance PHP developer for a defined job, or a dedicated PHP developer who keeps an application moving month after month. I offer both. Project work gets a written scope and a fixed quote. Ongoing work runs as a part-time dedicated arrangement: reserved hours each month, your backlog in priority order and the same engineer every week.

My experience is real production PHP. On an AI invoice capture project in CodeIgniter 3, I was the dedicated developer across four businesses' ERP/CRM systems for four months, building the OpenAI invoice scanner and a staged, logged sync with their accounting system. I also customize Perfex CRM and maintain CodeIgniter applications, and work daily in PHP 8 and Laravel.

Working with me as a core PHP developer means you talk to the person changing your code. I work remotely with clients in different time zones and we agree on update times at the start. You keep full access to your server and repository, and every change is documented so the next developer is never starting blind.

I do not publish prices. You get a fixed quote after a short call or a written brief, and for unclear legacy problems I quote a short paid investigation first so the main quote is based on facts. The main cost drivers are:

• The state of the code. Clear structure with some tests is quick to change; one large file per page with mixed SQL and HTML takes longer.
• The PHP version gap. Moving from 7.4 to 8.3 is a smaller job than moving from 5.6.
• Access and environments. Without a staging server or a copy of the database, part of the work is creating them.
• Integrations. Payment, accounting and shipping APIs each add testing time.
• Documentation. If nobody knows how a module is meant to behave, finding out is part of the job.