HackerRank - HackerRank is a platform that allows companies to conduct interviews remotely to hire developers and for technical assessment purposes.
Python - Python is a clear and powerful object-oriented programming language, comparable to Perl, Ruby, Scheme, or Java.
iMocha - Make intelligent talent decisions.
Rust - A safe, concurrent, practical language
Codility - Codility provides a SaaS platform with advanced validation, security and protection features to evaluate the skills of software engineers.
Java - A concurrent, class-based, object-oriented, language specifically designed to have as few implementation dependencies as possible