Your visa does not expire the moment you graduate. You are granted an official 18-month job-seeking right (Job-Seeking Visa).
During this process:


When you find a job related to your field and your annual gross salary exceeds specific threshold values, you can obtain an EU Blue Card.
For 2025-2026, this is approximately:
The Blue Card grants you:
Permanent Residency (Niederlassungserlaubnis)
Graduates from German universities can obtain indefinite residency much faster than other immigrants.
You can apply after approximately 2 years of working regularly and paying insurance premiums. Thus, Germany is not just a country for education; it's a country where you can build a career and a life.