as constmakes the attributes of an object constant, and does the same thing like Object.freeze(), yet not a runtime. Therefore, it makes sure TypeScript understands that the provided type for the attribute stays the same.
It is often a useful fix when the pure constdeclaration is not enough.

const person = {
	name: "Max", 
	age: 22
}

function takeString(param: string) {}

// will give a warning, that person.name might be any, as attributes are not constant
takeString(person.name)

Solving this problem:

const person = {
	name: "Max", 
	age: 22
} as const