I have over 16 years experience as a software engineer and technology leader, including over 9 years experience specializing in Android Mobile apps development. I currently reside in the US, and work primarily as a hourly-contractor.
Currently I am seeking full-time employment opportunities for career-growth.

I have never used Kotlin professionally, although it's been 4 years since Android has become Kotlin first.
I have learnt Kotlin as a personal effort only, and I can do everything and anything Android using Kotlin, fluent and comfortable.

However, I am not fully comfortable using Kotlin functional-programming, declarative-style, operator-chaining for data-structures and algorithms problems. I have been using Java for 16 years, so I can begin thinking only in Imperative-style, verbose Java type code as solutions. I am also not very well-versed in Java Streams as yet, because Android for the most-part, did not support Streams as much.

When I tell recruiters and interviewers about my choice of Java for Data-structures & Algorithms problems, and Kotlin for any Android sample project code-base, bug-squash type interview rounds, I am automatically getting rejected.

1. No Professional Kotlin experience - is it my fault that every project and work-place did not use Kotlin, including my current project ?
2. Kotlin coding-speed, particularly no skill for functional-programming, operator-chaining solutions.

I feel discriminated. I am seeking a Kotlin mentor, so I can learn best practices functional-programming solutions for data-structures and algorithms, as well as Android.