About Laszlo

I’m Laszlo Kosa. I’ve been writing code on the web for more than 20 years, the last 10 of those focused almost entirely on WordPress and WooCommerce. I live and work in Budapest, on Central European time.

This site exists because most of what I do day to day is one specific thing: making WooCommerce stores faster, fixing the ones that have stopped behaving, and keeping the high-stakes ones running. That’s what Grow Revenue Expert is, the front door for that work.

20+ years of commitment to shipping solutions

The first commercial site I built went live before WordPress existed. Since then, I’ve worked across PHP, MySQL, vanilla JavaScript, jQuery, and the front-end stack that goes with all of it. I’ve shipped custom themes, plugins, and full WordPress builds. I’ve migrated stores between hosts, between page builders, and between database versions.

What I bring is range. The kind of range that comes from the experience across hundreds of projects.

Why WooCommerce performance

I picked this lane on purpose. WooCommerce stores running real revenue are a category where small technical wins translate into real money fast. A 1.5-second speed improvement on a product page can recover hundreds of dollars a month on a $30K/month store, every month, forever. That’s a kind of work where the value is honest and easy to measure.

The other reason is the gap. WordPress developers are everywhere. But specialists who think like a business strategist, who optimize for revenue impact, not just technical metrics, are rare. That’s what sets me apart.

How I Work

A few principles I won’t break:

Minimal plugins

If a problem can be solved with a few lines of clean code, that beats a complex and large plugin with a large number of settings you’ll never use.

Investigate & understand before change

Most of the first hour on any new engagement is reading the codebase, the logs, and the history. The fix is faster when you understand the system.

Measure against real traffic

Lab scores and synthetic tests are guides. Real-user metrics are the truth. Both matter.

Document what I touch

If you bring another developer in next year, they should be able to read what I did and why.

The investment pays back fast

Speed optimization typically recovers its cost in 1–3 months of recovered revenue. Every month after that is margin.

Stats

Codeable Top 3%

For the last four years, I’ve taken contracted client work through Codeable, a curated marketplace where fewer than 3% of developer applicants get accepted. Codeable is the back-office for contracts, escrow, and payment on most of my client work. It’s how the legal and financial sides stay clean for both sides.

Public track record on Codeable as of this writing:

5.0/5 overall rating

With a lot of magnificent reviews.

220+ completed projects

About 30% of the sum value on high-frequency e-commerce sites.

57 customers

And of course, a hundreds more outside of that platform.

The reviews are public and unedited on my Codeable profile

Day-2-Day

Tools and stack

Languages: PHP, MySQL, JavaScript, jQuery, HTML5, CSS3, Sass
WordPress: Custom themes, Gutenberg / Block Editor, ACF, custom plugins, WPML
WooCommerce: Core extensions, custom payment and shipping logic, subscription and membership setups, LearnDash
Page builders: Bricks, Elementor, Crocoblock – when they’re the right tool, not the default
Performance: Query Monitor, Core Web Vitals tooling, Redis/Memcached, server-level caching
Hosting: Comfortable across Kinsta, WP Engine, Cloudways, SiteGround, self-managed VPS, and many more

Unity

Outside the work

When I’m not in WordPress, I’m building games in Unity on the side under a separate brand. Different audience, different skills, same instinct: solve the problem and, as a plus, have some fun.

Ready to speed up your business?

If you’re a WooCommerce store owner looking for a senior pair of hands, the next step is short.

Apply to Work With Me