App Store ranking factors
The signals Apple uses to order search results — chiefly text relevance, download velocity, engagement and ratings.
Apple has never published a ranking formula, but the inputs are well established from documentation, WWDC sessions and a decade of observation. Text relevance comes first: your app name, subtitle and keyword field determine which queries you are eligible for at all. Nothing else matters if you are not in the candidate set.
After eligibility, the ordering is driven by behaviour. Download velocity for that specific term, tap-through rate from search results, retention after install, and rating volume and average all feed in. Ratings are load-bearing in a way that surprises people — both the average and how recent the reviews are.
Two consequences follow. First, ranking is per-query, not global: an app can sit at #1 for a long-tail term and nowhere for its category head term, and that is normal. Second, conversion signals are ranking signals, which means screenshot work is ASO work. A set that lifts tap-through from search lifts the ranking that produced the tap.
What does not appear to matter: keyword density in the description (not indexed on the App Store, unlike Google Play), backlinks, or update frequency on its own.