For the brains of the macro pad i used a C-Duino. https://github.com/mustacheman6000/C-Duino

It's a Pro Micro clone with a Usb-C port.

For the software i first made a keyboard layout with keyboard-layout-editor.com and then used kbfirmware.com to get the .hex file which i then flashed onto the microcontroller.

The bottom part is just screwed into the top part with some wood screws.

Switch grid layout. I used Gateron blue switches (https://www.aliexpress.com/item/1005001445172978.html) and 1N4148 diodes (https://www.aliexpress.com/item/4000928651264.html). For the keycaps i used some metal ones.