Robotics / ROS
Also written as ROS, ROS 2, Robot Operating System, Robotics Engineer, Robotics Software
ROS (Robot Operating System) is the standard open-source toolkit for robot software, handling how sensors, motors and planning code talk to each other. Despite the name it isn't an operating system; it runs on Linux. ROS 2 is the current version, and ROS 1 has reached end of life.
Think of it like
A car's wiring harness, which lets the engine, sensors and controls all talk to each other.
Junior or senior?
Robotics mixes software, maths and hardware, so find out which layer they worked on: perception, motion planning, control or hardware integration.
Senior sounds like
Has deployed on physical robots and debugged timing or sensor problems in the field.
Ask them
“Which part of the robot's software did you own, and what broke when it left the lab?”