Git
Also written as version control
The standard tool for tracking changes to code over time and enabling multiple people to collaborate on the same codebase without overwriting each other's work.
Think of it like
Like a video game's save-file system for code — you can always roll back to an earlier save, and multiple people can play different save slots without overwriting each other.
Junior or senior?
Junior sounds like
Avoids anything beyond add/commit/push.
Senior sounds like
Can walk through a messy merge conflict they untangled or lost work they recovered.
Ask them
“Tell me about a time you had to untangle a messy merge conflict or recover lost work with Git.”
Sounds like real experience
Walks through the actual commands and reasoning used to resolve a specific conflict or recover lost work — not just 'I use Git for version control.'
Probe further if
Describes Git only as 'saving and pushing code' without a specific merge conflict, rebase, or recovery situation they actually had to work through.