Does anyone else find the 'Job' menu extremely slow to open? In particular this is when opening it with the intention of giving a bitizen 'No Job' and then cycling in a newer bitizen with the aim being to earn bux for giving them a dream job (not that they seem to do that every time since the last update - not sure if that's a bug or intentional). I have ~200 bitizens and ~135 levels and a Nexus 4. Everything else in the game is fast.
I have the same issue playing on an iPhone5, 136 levels and 207 bitizens. I think it's a lag due to the vast number if bitizens to load.
When cycling new bitizens into jobs, it's probably easier to employ them via their dream job level (i.e. Go to that level and evict/unemploy a bitizen, then click "hire bitizen". The most suitable bitizens appear at the top - dream jobbers first). Hope this saves you a bit of time, but I don't think there is a solution to the lag problem.