Grepthor Software Solutions Python Developer interview questions

interview had 3 rounds. aptitude technical HR aptitude was easy. technical was average not to difficult. they asked java multithreading and python basics and diff b/w java and python. HR was also easy. they asked about my self and asked my regretful moment. the entire process took 2-3 hours but after two days they call back saying your not selected and we are ready to take backdoor are you interested.