Is it difficult to create an engine like Unreal engine 4?

Question

Game development

After all, there is an advanced GUI, and much more.
What kind of team do you need, how many people?
What specialists are needed?

Answer 1

For my third time in a day I throw this link:
https://tproger.ru/translations/how-to-learn-gamed...
There is also about the development of engines. But to develop an engine, you need to have knowledge from all other areas.
Your question is generally akin to "how to build a rocket like Elon Musk."

Answer 2

Very difficult.
Lots of specialists. The quantity depends on the detailed TOR and development time. Few specialists - longer, many - faster, but not everything can be parallelized.
Developers, testers, architects, managers, maintenance personnel.

Answer 3

Yes