Based on our record, Facebook Design Resources seems to be more popular. It has been mentiond 2 times since March 2021. We are tracking product recommendations and mentions on various public social media platforms and blogs. They can help you identify which product is more popular and what people think of it.
Spotify isn't doing anything unique here, and it's not really a marketing campaign to explain away their UI. It's more of a showcase for hiring professionals, developers/designers/etc. Facebook has a similar one -> https://design.facebook.com/. Source: almost 3 years ago
Also, read anything published by Design @ Facebook. Source: over 3 years ago
Designer Mill - Collection of Best Free Design Resources
AdRoll - AdRoll is a leader in retargeting display advertising. Draw the right people with the right strategies.
Interfacer - Collection of more than 200+ free design resources
Marin Software - Optimize your Search, Social & Display ads across channels and devices. Marin Software, the leading cross-channel performance advertising platform.
Freebiesbug - Collection of the best free web design resources.
Google Marketing Platform - Google's unified and improved marketing and analytics tools.