EMB ERJ 145 ER/LR
Flight Crew Multiengine; Flight Crew Air Transport Pilot (ATP); Flight Crew Instrument
Fatigue
No Specific Anomaly Occurred Unwanted Situation
General None Reported / Taken
Company Policy; Human Factors
After 4 days of giving new hire FO IOE I was exhausted. We finished up our four-day trip just about 2.5 hours late due to maintenance issues and an understaffed airline.  The four-day finished at XA30pm. I then had to take the employee shuttle from the terminal which took time. I finally drove home to my place and made it to sleep around XDam [two and half hours later]. I did my best to sleep and I was unable to get adequate rest for the 5 legs I was supposed to fly on my 5th straight day of duty.  The sign in was supposed to be 12 hours on the dot almost from when I finished my 4-day trip.Cause - Understaffed airline forcing us to do the last turn of the four day. The last turn resulted in maintenance issues and required a plane swap. Due to this flight; we were 2.5 hours late and I was super tired from doing 2 straight weeks of IOE.
EMB-145 Captain reported going to work while extremely fatigued and attributed the challenging schedules to staffing issues at their company.