Prosperity and prosperity are the most commonly used words, both of which refer to prosperity.
During the boom,
A prosperous era
prosperous period
A stage of prosperity.
In addition, you can use summers, which also means orgasm. For example:
Every civilization has its birth, climax and decline.
All civilizations go through birth, prosperity and decline.
If you mean the heyday of a person, such as the heyday of an athlete, you should say
noontide
Terminal can also be used here.
The pinnacle of one's career.