A rest parameter in a JavaScript function must be the last parameter of the list:
// Does not work
function example(...arg, value) {}
// Works
function example(value, ...args) {}
However, you can use the rest syntax for an array type in TypeScript at any position.
// Expect a list of strings and one number as last parameter
function example(...args: [...string[], number]) {}
// It can also be in the middle of an array
type Example = [boolean, ...string[], number];