Great breakdown! I've been diving into Spotify's API for my research at Soundify Premium, specifically looking at how metadata affects stream loading times. Have you noticed any significant latency differences when fetching large discographies vs. single tracks? Would love to hear your thoughts on optimizing these requests!
I'm primarily tracking client-side TTFP. The divergence is real—server-side metrics often hide the 'last mile' handshake delays, especially on mobile. Batching those track IDs really is the only way to stay under the rate-limit while keeping the UX snappy. Thanks for the heads-up on the popularity TTL; that’s a tricky one to balance! Anyways great observation on the /audio-features latency! I noticed a similar trend with different storage tiers during my performance audit for Soundify Premium.