If you meant something else (e.g., analyzing Spotify app features, building a music player, or reviewing RevDL as a topic), say which and I’ll help.
If you want Spotify Premium, pay for it. Use a free trial (one month free for new users). Ask a friend for a Family plan invite. But never, ever download a Spotify mod from Revdl or any third-party site. The risk is real, the consequences are severe, and the "premium features" are always broken.
Searching for "Spotify Mod Revdl" is like searching for a free steak dinner in a sewer. Even if you find one, you won't like what you have to wade through to get it.
Spotify updates its official app every two weeks. A modded APK, on the other hand, relies on an unpaid hacker to reverse-engineer each update. By the time you find a "working" version on Revdl, it is often 3-6 months old. Eventually, Spotify forces a server-side change that breaks the mod entirely. You open the app and see only a blank white screen. Your only recourse is to uninstall and hunt for a newer mod—restarting the cycle of risk.