let is of course, not imperative in elm, it is an expression that evaluates to a value. Do you mean that the antipattern created had to do with many untyped functions inside let?
For example, TEA architecture is simple, but when you have to make a component library using this architecture, then they just can’t figure out how to do it. I have seen so many weirds patterns, which just makes codebase unmaintainable and pain to work with.
I think this is one of the most underestimated challenges in elm.
I have watched many talks and read about how one should change his “component” mindset to something else, to collections of functions. And many times, with the help of good examples I thought I grasped it. But after years of elm, I am still unsure how to make something of good quality that serves the purpose of a component library. Even if it isn’t true, React still feels ideal for building a set of UI tools. With elm maybe there is no one pattern, which is alright, but one has to deal with this when selling elm to any team that is looking for “component” patterns.
I have found this very difficult to do.