I am going to sign a new contract in a start-up. As we discussed the pay, they warned me a part of the pay was variable. They intend to pay it all the time and partly or totally remove it in case of professional fault, to paraphrase their wording. They implemented this after bad experience with previous programmer who came only when he wanted to and they had no possiblity to fire, and made it very clear they did not intend to use it as "motivation" or objective-based tool.
This seemed very odd to me. I am not a lawyer, but I tried to search if what they were planning to do could make it into the contract, but I found no similar case. From what I understood though, it seems that in my country (France), variable pay can only be made by objectives contract and can be claimed fully by the employee if the employer failed to provide an objective proof they were not fulfilled (this is mostly used for commercial commissions).
I want to make things as clear as possible and even warned them about the consequence of lack of objectives, but they simply assured me they would make it clear in the contract. They sounded like they didn't want to bother right now.
Should I pressure for more details now, while i'm quitting my job, or when the moment comes to sign my new contract ?
EDIT: What happened next
I see this topic is getting more answers so I'm giving a bit of feedback of how I am coping with the situation.
I asked them for more precision by e-mail before I sign the promise, knowing that whatever they answered had legal value and had high chances to be what would be in the contract. They wrote me back the objectives would be both qualitative (respect of processes, implication, motivation) and objective-based (features etc.), so their answer was different than what they originally stated.
That does mean they have a lever of pressure there, however, being confident of my own performance, not being in need of any penny of the variable amount which is pure bonus compared to what I currently earn, and considering I also have advantages regarding work time, place, and job interest, I am fine with these conditions.
I can see most of you consider having a variable pay as a symbol of distrust or poor management ability or both because you consider this 10% as a potential malus (and I think it's a mistake by them to have it presented to me this way the first time), while truely it is potential bonus, that they are, according to them, giving away for doing average. Devs might not be sellers, but bounties can be motivating to anyone, and I can understand a manager wants to keep his devs motivated. Giving money reward has nothing inhuman :). In itself, the money isn't a problem, if I never gain it it's still "OK" the problem would be the lie, not the money.
This is my POV and I'm 99% sure there will be a huge flow of disagreement, but my answer is this: is it better I make my own experience if this model fits me, or that I trust people that don't know me saying it wouldn't ?
Note that I made my own judgement on the employer, he look friendly/honest/fine. This was a two sides interview, I am not jumping on the first opportunity blindly.