What is the Shariah-compliant percentage of revenue that can be allocated to a software maintenance engineer or technician, taking into account that the company bears all expenses, and how does this percentage change if the engineer shares in bearing losses or does not share?

Some jurists, such as the Hanbalis, have held that it is permissible to deal with a software engineer by giving him a percentage of the profit, by analogy with musaqah (irrigation contract), muzara'ah (agricultural contract), and mudaraba (profit-sharing partnership). In these cases, it is permissible to give an animal or a machine to someone who works with it for a portion of its rent, because it is an asset that grows through work, so the contract is valid with a portion of its growth.

On the other hand, the Malikis considered this dealing to be a فاسدة (invalid) hiring due to the uncertainty regarding the amount of the wage.

If a loss or damage occurs to some devices, the responsibility falls on the employer, because the worker's hand is a hand of trust (يد أمانة), and he is not liable unless he has been negligent.

Determining the worker's percentage of the profit is subject to the agreement between the two parties, and they must be tolerant in their dealings.