How much working time to spend on the analysis of someone else's code?

Question

reverse engineering

Hello everyone,
10 months experience in python.
I recently got a new job. The essence of the work is that I disassemble someone else's open source application in order to make a commercial release out of it.
There is no documentation on it, the cat cried comments.
The application is really large and complex, at the level of systems of large corporate monsters of the oracle level.
There is a lot of code, modules and libraries used.
I can’t name the application, maybe privacy.
The pay is good, I'm not complaining.
But at the moment, all I do is ONLY dig into other people's code.
The upside is that the code is well structured (i.e. not shitty code)
(Python and js)
I understand what the application does, I understand the mechanism in general, but I absolutely do not understand why this or that module is needed.
Unfortunately, I have very limited access to the authors of the application, there is practically no one to ask.
As a result, it takes me a month to redo some little thing (relatively small thing).
So, is this normal?
How to determine whether this path leads to development?

Answer 1

Well, if you are paid and not scolded, then the employer is satisfied with everything and he has a reason to do it)) Although, of course, the fact that you don’t understand parts of the system is not buzzing. No comments or documentation?

Answer 2

If it's legal and profitable, then fine.
if not legal, but profitable, then criminal.
if legal but not profitable, then it is a hobby.
if not legal and not profitable, then this is a diagnosis.