Built from real-world WooCommerce problems

InstantStack was founded by Tom van den Hengel, a WordPress and WooCommerce developer and owner of WebKenner. InstantFilter didn’t start as a theoretical product idea, but from recurring performance issues in client webshops.

• Developed from practical experience
• Focused on WooCommerce performance
• Built and maintained in the Netherlands
• Transparent technical approach

The problem behind InstantFilter

Traditional WooCommerce filters execute a heavy process on the server with every interaction. They make an AJAX request, boot up WordPress entirely, run complex database queries, process the product results on the server, and then send new HTML back to the browser.

For webshops with many products, attributes, and variations, this inevitably leads to problems:

• Noticeable waiting times for the visitor
• High server load (PHP worker exhaustion)
• Poor scalability during traffic peaks
• Complex caching exclusions
• An inconsistent and sluggish user experience

“While working on larger WooCommerce stores, I kept running into the same issue: filters felt slow, even when the rest of the shop was perfectly optimized. The root cause was rarely the hosting or caching, but the architecture of the filtering system itself.”

Why InstantFilter was developed

From that frustration, a simple question arose: What happens if the browser does the filtering work, instead of WordPress on every click?

The result is the client-side architecture of InstantFilter:

• Product data is pre-indexed on the server.
• Filter data is efficiently packed into a JSON codebook.
• Filtering happens entirely client-side in the visitor’s browser.
• No AJAX round-trips or database queries are needed per filter action.
• Filter calculations typically resolve within milliseconds in suitable configurations.
• The initial data is perfectly cacheable by systems like WP Rocket or Redis.

The developer behind InstantStack

Tom van den Hengel is a WordPress and WooCommerce developer and the founder of WebKenner and InstantStack. He develops custom solutions for webshops, with a strong focus on performance, scalability, and user experience.

InstantFilter was born from recurring issues he encountered in client projects. Existing filter solutions often relied on heavy server requests, complex queries, and long waiting times. Based on that practical experience, he developed a client-side architecture where filter actions don’t constantly burden WordPress and the database.

Tom works daily with WordPress, WooCommerce, PHP, and JavaScript, building solutions for product feeds, API integrations, large product catalogs, custom filters, and webshop performance.

Practical experience as the foundation

The technical choices behind InstantFilter are directly shaped by projects with large product catalogs, variable products, and complex attribute structures. As a result, the focus isn’t just on speed, but also on maintainability, scalability, and predictable behavior for developers.

The architecture is designed to robustly handle challenges such as:

• Webshops with thousands of products and tens of thousands of variations.
• Complex product feeds and automatic stock synchronizations.
• Performance bottlenecks caused by slow WP_Query and AJAX calls.
• Compatibility with existing page caching and object caching.

Our development principles

No black box

InstantFilter isn’t just marketed as fast. Our documentation explains exactly how the indexing, data layer, caching, and client-side filtering work. This allows developers to assess for themselves whether the architecture fits their specific webshop.

Verify our approach

We believe in being open about our technology. Check out the resources below for a deep dive under the hood.

• Technical Documentation
• Performance Explanation & Benchmarks
• Changelog & Updates

InstantStack as a company

InstantStack develops specialized performance tools for WordPress and WooCommerce. The focus is on solutions that structurally address existing technical bottlenecks, rather than just masking them with extra caching or more server capacity.

InstantStack is the product organization behind InstantFilter, founded from the development studio WebKenner. Development, maintenance, and support are fully handled in the Netherlands.

Trust and transparency

We value clear communication and accessibility. Here you’ll find all important company and legal information at a glance.