The combination of glue code and pipeline jungles are, along with feature engineering, one of the biggest pain points we've observed in users. This stuff gets copied and pasted everywhere, turns unmaintainable, and then is next to impossible to optimize.<p>It's as if a lot of ML framework authors believe that most users are researchers... in reality, data is rarely clean, rarely in the right format, and usually needs to be intermingled and transformed with other data before it can be useful.