> I wonder what starting point and success criteria do you assume for that 2 year timeline. About a year ago I wrote a deferred renderer with dynamic lights, and shadow mapping, and few post effects in about a month of free time (Less than a week of full time work).

i'd assume it means fully understanding what you're building, if you already know 3d graphics or are just copying example code around, sure you can build something quick, but to fully understand the concepts from a background without previous graphics knowledge takes time and dedication