BIS Safety Software Software Developer interview questions

It was very long process. interview 1: 30 min HR interview interview 2: 30 min Technical Interview interview 3: 3 hr coding interview + 2 hr for additional changes interview 4: 1 hr in person interview I thought everything was going well since I did really well on all the interview and after spending 6 hr of my time and keeping me waiting for 2 weeks I hear back that I didn't get the role. Im not sure why but the for the amount of time spent it was really disappointing to not get the job.