I really hope that Paradox will fix the Mid/Lategame Lag with the next patch and the easiest solution would be to reduce the calculation of pop jobs to once per month instead of once per day. Sadly this is hardcoded so that i cant fix it by myself but it should be easy for Paradox anyway. i dont need all my hundreds of billions of citizens (or slaves) to rethink the decisions they have done in their lifes and the jobs they are working at every day!