Is it permissible to seek the aid of an intermediary to obtain a job position in a competition based on certificates, knowing that some or most of the candidates do so?

Legitimate mediation to employ a competent person for a job is a good and praiseworthy intercession according to Islamic law, and there is no injustice in it towards anyone. This is based on the Prophet, peace and blessings be upon him, who said: "Intercede, and you will be rewarded," and "Whoever fulfills the need of his brother, Allah will fulfill his need." As for bad intercession, it is that which is for an unlawful matter or involves injustice, based on the Almighty's saying: "Whoever intercedes with a good intercession will have a share from it, and whoever intercedes with a bad intercession will have a burden from it."