Performance issue in the js release
At the moment the js generated code is almost unusable due to major performance issues. The problem is to be found in the type checking mechanism implemented in the Kotlin js standard library. This problem has already been signalled to the Kotlin development team (https://youtrack.jetbrains.com/issue/KT-24784?_ga=2.158199160.336827958.1602082398-1861126620.1599731750), but at present haven't been provided possible solutions.
From our perspective we could try to mitigate the problem replacing the use of is and as operators, the ones that are transpiled in the problematic isType function, with a custom mechanism to verify the type of our entities. In fact, a massive use of the isType function is linked for example to unification (mgu) or substitution (applySubstitution).