Get a beer with a particle physicist some time, you will find most of them didn't actually work on "finding dark matter" but worked on a myriad of specific technical challenges.

- Superconducting magnets and power distribution

- Radiation hard ASICs and detectors

- CAD software like KICAD

- ROOT

- Grid computing infrastructure

- Analog circuit design (1024 channel low power ADCs, pixel sensors)

- FPGA design for data aggregation and communication