I have coworkers doing that without a degree. They did however show up with experience.

Personal projects will do. You could work on Open Source software. Obvious choices: qemu, valgrind, FreeRTOS, RTEMS, Linux (kernel), SeaBIOS, gcc, clang, ghidra, binutils, MAME, OpenOCD, gdb, dosemu, dosbox, FreeDOS, Wine, SDCC, dolphin-emu, Xenia, coreboot