That sounds like torture to me. Don't exceptional developers' portfolios and resumes say enough that they don't need to suffer through all that to get a great job? Are the exceptional developers really the ones applying for your job in the first place?
This isn't the worst interview process I've ever read about. I've heard of developers applying to jobs at Microsoft getting 3, 4, 5 levels of interviews before finally getting a job. But most of the developers I met at Microsoft were competent, not exceptional. Exceptional developers didn't need to waste their time with that kind of process and they know it and they moved much more fluidly between jobs.