around 2 to 3 years imo.

It's an employee's market now, so unless you're bonded to someone, spending 2 years in a place would get you a good chunk of knowledge of the tech stack, and gain some proper experience outside of just fooling around and learning the stack.

After that, jumping could get you a 15 to 25% salary increase, and/or unlock the US west coast opportunity with their high 200k first year TC.