I am targeting a specialized work which hopefully would pay well. For example, someone working on the Google Spanner DB. Full stack is better paying, but afte

I am targeting a specialized work which hopefully would pay well. For example, someone working on the Google Spanner DB. Full stack is better paying, but after some time it feels like doing the same thing over and over again. What downsides do you foresee in making the career shift? (Apart from a risk to salary)