TekRevol interview questions

They ask general question related to Solid principals, OOP, framework(Laravel middleware, ORM, Queues)and MySQL basics. And also they ask me to design Instagram ERD by given its feature list. The interview goes very perfectly and answered most of their questions but still got the mail that I was not selected. I don't know why interviewer seem so much convinced with my answers and didn't select me. I thought it was budget issue, because that manager ask my current and expected and after that I feel negative expression by his side. The interview goes around 1 hr. that's all in verbal or writing on a paper.