Is It Important to Have a Principal of Mobile Developers in a Corporation?

Let's talk about the career tracks of a mobile developer at high levels. Together with mobile development leaders at Yandex we will figure out who are principal, senior and staff developers, what tasks can principal solve in the context of mobile development and can we replace high-grade colleagues with a few middles?

At the BoF, in contrast to talks and roundtables, there is no division into participants and presenters: here everyone interacts with each other as equals. The main thing is not to off-topic and discuss the topic.