Hello sir, my name is Kevin Carvajal.
I have a lot of experience in software development in JAVA, I see that it needs to be specifically in java, I guess you need details for the correct understanding of the code, if this is so, I promise to deliver the necessary documentation and quality of work. If you do not need complete understanding of the code, it does not matter, I will be available if you need changes.
I'll be waiting for more details of the work.
Thanks.