What is the reason for a young man's lack of success in obtaining a job or completing an engagement, despite having the required qualifications and specifications, and is there something hindering his life?

All that afflicts a servant is by the decree and wisdom of Allah. Allah may avert something from him to reserve for him something better, as stated in the Almighty's saying: "But perhaps you hate a thing and it is good for you; and perhaps you love a thing and it is bad for you. And Allah Knows, while you know not." If a calamity befalls a servant, he should accuse himself and renew his repentance, for tribulation does not descend except due to a sin, and it is not removed except through repentance. This is in accordance with the Prophet’s (peace and blessings be upon him) narration from his Lord: "So whoever finds good, let him praise Allah, and whoever finds other than that, let him blame no one but himself." The servant must hasten to general repentance, strive in righteous deeds, increase in seeking forgiveness, and maintain the prescribed supplications and incantations, while having a good opinion of Allah and supplicating Him frequently.