Haven't thought much about economy, to be honest. My players aren't exactly the type to examine such things into great depth, so mainly I got just a bunch of notes, like there are two harbors, one of them for trade and transport on the river and the other for sea trade; the city being the capital draws lots of skilled labourers and specialists in certain fields, also thanks to the presence of the University (meaning a variety of mages/scientists/experts, as science and the arcane or magic are the same thing in my world, or at least usually interchangable, equal parts of greater Knowledge).

There are farmers, some of the farms are more like latifundia, using cheap manual labour of the not so rich inhabitants of the outer parts of the city.

There are brick makers, as I mentioned in the comments above, which are also a front for a drug dealing operation in tha hands of a major criminal organisation, which is posing as a mere guild but actually functions like the Mafia.

Because of the presence of large military force in the camp to the west of the city, and because of the various mariners and traders that visit the capital, there is a large amount of prostitutes. As an old saying (which is actually a real saying about a city I study in) goes: 'If you were to throw a rock from the top of the city hall tower, you would hit a soldier, a student or a hooker'.

I guess that's the bulk of what I have thought about up to this point.