All candidates should:

have a desire to take on responsibility and direct their own work with minimal overhead management
have a B.S./M.S. Degree in CS or CE (Computer Science or Computer Engineering)

All candidates must:

have proficiency in python, git, and repo
have systems level Linux experience and proficiency as a first-choice development platform (toolchains, containers/sandboxing, open embedded/yocto, CLI: bash, python, Linux boot and runtime processes, systemd, networking, etc.)

Bonus domains of expertise:

micro-controller (< 8K RAM, 8051, ARM m0-m4, ...)
Yocto, bitbake, Docker (used to automate embedded build environments)
C/C++ development (minimally have insights into resolving build errors/regression)
u-boot, Linux kernel experience (configuration, build, etc.)