I've had my introduction to the 40% world with this handwired, 3D-printed, ortholinear board. It was a blast (first time soldering) and I'm looking to extend myself a little further with soldering, qmk and 40% layouts (but probably not designing something completely from scratch yet). Anyone got any suggestions on what I could build next?

What kind of machinery is that in the background?

That's what I'm wondering too

my uneducated guess, a telecommunication equipment for some testing?

Good guess! This is my work desk, it's one of our core products, an industrial cellular data logger with a range of features. Usually housed in a large stainless steel enclosure with solar panel and battery. This is a "naked" one on my desk, and the black plastic box to the right of it is a glorified place to mount my buttons and switches for it. The white thing on the left is a temp sensor made in house, with solar radiation shields so it isn't affected by the direct sunlight.

Usually used for serious solutions, our desk ones are for fun/testing, i.e. there's a sensor on the front door that connects to this via UHF radio, when the door opens the logger flashes the LED for 5sec. We design and build these in house, we have our own SMD plant.

So this is pretty much a raspberry pi?

The business made the first generation of these back in 2003, it's geared more toward industrial use cases for remote data logging using a built in cellular or satellite modem. Yeah you can do the same kinda stuff with an rpi but our design is built around a specific use-case.