(someone's) challenge is (someone's) opportunity

Translations
чей-то вызов — это чья-то возможность
His challenge is her opportunity to demonstrate her skills.
Его вызов — это её возможность продемонстрировать свои навыки.
Definitions
This phrase means that a difficulty or problem faced by one person can be seen as a chance for success or advantage by another person. It highlights how situations that are obstacles for some can create openings or benefits for others.
Words
challenge

noun
вызов
opportunity

noun
возможность