I'm an engineer at Illustrative Mathematics. Here's what I know: Eureka Math is derived from EngageNY. Illustrative Mathematics is an openly licensed, freely available curriculum which was developed independently from EngageNY. You can learn more about it at http://curriculum.illustrativemathematics.org.
Thanks! Cynical I may be but I do love our mission at IM.
And I'll just leave this here because at work we were all laughing our heads off about it. We joked about hiring the author to write practice problems for us. ;-)
Location: REMOTE (US only)
We are a nonprofit edtech focusing on K12 math education.
Details: https://illustrativemathematics.applytojob.com/apply/46MWwBt...