Yup, worked in a US lab back around 2005. Now back in the EU, I find that in most areas online stores have caught up, but on hardware nothing yet comes close to McMaster-Carr.

One thing I only realized when living in the US is that the reason that online shopping is so much more advanced in the US than in the EU is not just the more homogeneous market. Due to tax rules (state sales tax on mail orders) mail order has always had a competitive edge in the US, leading to a many companies already being set up with a deep back-catalogue and strong inventory metadata when the internet hit.

Same here. I have no tool/hardware needs at the moment but I'm having a blast navigating the site.

I think one of the reasons that it is so fast is that all the small images are monochrome PNGs. Really well thought out and to my eyes it looks rather stylish.

Yeah, it's way better than Conrad or Manomano, who both use the same shitty layout you get from every etailer : gigantic full-page promotional material and some top categories in the middle to start navigating things. And in the end you have to tinker with filters for 5 minutes before narrowing it down to probably maybe the right part.

It's kinda small for my liking, but I've got a big screen and didn't bother zooming in. Only niggly thing is that page clicks create a spinner; one thing they could do to improve is to pre-render everything, given that what I clicked on was just category pages.

I've had great experiences with Gatsby on Netlify in that regard, we've built a number of websites using it. With Gatsby you get the benefits of a React webapp but without the downsides, things like preloading on hover, instant rendering, service workers acting as content caches, etc.

I work a lot with distribution/manufacturers and I always use McMaster as the de facto way to do things.