In a famous scene with John Hammond and Nedry, Nedry says that he is the only one who can debug 2 million lines of code. So after that scene and with my frustration I googled and some websites say that 2 million lines of code is equal to the Windows 3.1 operating system made with 2.5 Million lines of code approximately.
So is it possible that only one person can code/debug 2 million lines of code, and considering that the "Park" needed to be open to get some income profits, and to pay the investors?
Please consider the age of the character in that scene and many things like weekend time, holidays, family time and if the "character" became temporarily sick and etc. A few minutes after that, John Hammond told Alan Grant in the Travel Trailers that Nedry is conspiring with another character (Lewis Dodgson) so that time is not for "coding or work" or production related, so please consider that time like in the examples above.