Alumio has had a series of monthly online trainings.
You can re-watch them below.
Video
Timestamps
0:00 Intro
01:14 Alumio Placeholders, JMESPath syntaxes
04:18 JMESPath (query language for JSON)
04:50 Alumio Placeholders, JMESPath syntaxes (cont.)
13:55 Wrapping up