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

Stockfish fails to solve this puzzle on depth 25. White to move and win : r/ chess

strategy - Why doesn't Lichess' Stockfish suggest this bishop sacrifice? - Chess Stack Exchange

Stockfish fails to solve this puzzle on depth 25. White to move and win : r/ chess

Chess Skills: 2017

Any idea why Stockfish wants me to have sacrificed my bishop for a pawn? It is the way to win a pawn. But it loses a bishop with no compensation. : r/chess

Why can Stockfish give different evaluations at the same depth? - Quora

engines - Why does Stockfish evaluate this position as equal? - Chess Stack Exchange

2011 - Chess Skills

Best openings according to Stockfish