The most difficult thing when developing.

Cooperation with other developers is the most difficult thing. When you depends on others' module, in other words you must receive some data from them, you get to be very sensitive or being stressed as not being sure of its quality. When there is problem like bugs, you may check your module first before requesting others' checking. For others don't like to spend time on that which is less impirtant to them.

 

So having a good relationship with other developers is so important. And you must check the correctness of their data with unit testing or other ways. And remember your given data will have issue as others may change their code.

 

So, if you separate your module, it may be a good decision.

 

 

And the following is the next issue. Your software get complexed, if there is bug, tacking it is so hard. In that case, previous made unit testing module helps much. And for this unit testing, you must consider testability aspect of architecture from beginning. It may be very boring job because with beginning you may feel so busy. But as time flows, your debugging time will be bigger than your prediction. When debugging, divide and conquer approach is useful and effective. For that, your software architecture must support your approach.