What should I do if the source code I developed is infringed?

This is also the biggest headache for many software developers. Once you give out the source code, it is bound to happen, and even if you have evidence to prove that the code is yours, it is very difficult to defend rights, and prosecution is even more unreliable.

One way is that you don't give the source code, but only sell software and after-sales service. After the software is sold, if you need to modify the function, you can modify the software for them at a suitable price, or don't give the source code.

If your software has good economic benefits, you can also consider applying for a software copyright. Although you have copyright after the software is written, it will be more convenient and cheaper to defend your rights if you have a certificate.