At first everything was fine, but then the customer delayed with the payment to the diploma protection, although everything was done perfectly. There were claims about the choice of a programming language, although everything was discussed in advance and the language did not play any role as a work. Plus I made the customer a presentation to the diploma absolutely free, hoping for a "bonus", which is already apparently not coming. And so it’s okay, without considering that it was delayed with the payment and there were unfounded claims with a very high level of performance and clear compliance with the delay. Co-operation can be done.

I recommend cooperation, it’s okay.