You don't get any of the benefits mandated by Mexican Law, they do this by hiring you as an associate, and when you join this company you have to pay $100 mexican pesos for a share of stock (you have to pay them to work there). Also, when they offer you a salary, they don't tell you that tax deductions haven't been applied.
There is a lot of micromanagement involved. Managers don't trust that you're doing your job.
Overtime isn't payed, they have some whacky formulas to decide how much days off you get. You need to get a minimum of 2 days after the formulas in a month or you won't get any, and hours don't pass on to the next month.
It is very difficult to get a better job position, this normally happens when the person that was in that position quits. And you don't get a raise (which means more responsibility, same money). And don't let me start on raises, basically you don't get or you get very little money (like $1000 pesos a month, tax deductions not included).
They hire almost everyone that applies, which means that normally you get to work with a lot of people who doesn't even have a clue about what they are doing.
There is a lot of new people joining this company and a lot of people leaving it, they don't care about the people they hire or retaining them, you are just another code monkey there.
Also, the clients of this company get cheated, people are sold like senior software engineers when they don't even have a year of experience. What this means, is that you softtek charges for you as if you had a lot of experience, and you get paid less than the real experience you have.
And there are a lot of other things, but I'll let other people point those out.