Hello! Former engineering director for DisneyLife here. Most of the team wasn't allowed to move to Disney+ and have since moved on. The DisneyLife journey would make a great book, but doesn't really fit into a HN comment.
FWIW, DisneyLife was built by a team smaller than most YC startups. The core technology for DRM/streaming was licensed by another company. When BAM was purchased, the entire product got outsourced. The auth was a central service that we didn't own but were required to use. When I left, we had autoplay of next episodes.