Hatio Innovations Java Software Engineer interview questions

Coding assignment. 3 technical rounds. HR round 1st was coding assignment. One document of well-described problem statement was given. I have to code the application, write unit tests with best practices. 1st round was java fundamentals, design patterns and core computer science questions. 2nd round was with team leader. A code walk through of coding assignment and was asked how would I implement certain additional features and to code some of them. Two simple DSA questions. 3rd round with solution architect and CTO. Was extremely drilling for knowledge depth from resume and concept I knew. Explain challenges and projects with qualities described in resume. Core CS fundamentals questions like operating system, RDBMS, networking, compiler and object oriented design. Interviewers were extremely knowledgeable and friendly. Required knowledge and skills are quite high.