I successfully passed the technical interview and was selected for the HR round. Following the HR interview, they indicated they were preparing to extend an offer. However, during a one-on-one meeting with the project director, it became clear that he was disinterested in hiring me. He even disrespected me by saying, "Your resume has all irrelevant things that I can see. Tell me something that you have worked on seriously." A few days later, they informed me that they could only match my current salary.

Can you explain the main components and details of microservices architecture? What are the basic principles of Object-Oriented Programming (OOP)? Describe the architecture of AWS and its key components. Can you delve into .NET Core, specifically explaining how Kestrel works?