In a nutshell, this is what people mean when they talk about company culture. Unless the company’s hiring practices are terribly broken, the people they hire tend to shape & reflect the company culture. The more at ease you are with those people or in that culture, the more satisfying, enjoyable, and fruitful your work will be.
This is what kills me about many tech companies…company culture doesn’t come from arcade games, ping pong tables, exposed brick walls, or free cans of La Croix. Company culture comes from and is reinforced by the people you decide to bring into the organization.