Why does it take stockfish depth 35 to find mate in 7? - Chess Stack Exchange

My underlying question here is: What is depth? I know depth is supposedly the number of half-moves or plies from the starting position that it has calculated, in at least one line. But I feel this

Chess: Computer v. Human

Mysterious Chess Problem! Stockfish Can't See Mate In 9

Stockfish's search tree trying to find a mate in 2 visualized : r/chess

Chess Skills: 2017

engines - Is there a way to use Stockfish to see tactics that aren't necessarily great? - Chess Stack Exchange

PlayChessWithAWebCam - BITPlan Wiki

Acquisition of Chess Knowledge in AlphaZero – arXiv Vanity

Games – Campfire Chess

I though this move was genius, stockfish not impressed : r/chessbeginners