What is the ruling on a partner in effort being late for his daily work in a company, while he receives a salary and a percentage of the profits, without the other partners knowing about it, and is it permissible for another partner in effort to be late like him, by way of reciprocity?

A Muslim must fulfill conditions and contracts, for Allah Almighty says: "O you who have believed, fulfill [your] contracts," and the Prophet, peace and blessings be upon him, said: "Muslims are bound by their conditions." Therefore, it is not permissible for your friend to be late for work, nor is it permissible for you to be late for him. Rather, you must advise him and inform the partners. Moreover, combining a fixed salary with a percentage of profits is not permissible for a partner by labor. However, it is permissible for a partner by capital if his work is under a separate contract and not required of him by virtue of being a partner. As for a partner by labor, he only takes a percentage of the profits.