HubSpot Software Developer - Internship interview questions

Was contacted for a call with the recruiter, asked questions about the company. Given a online assessment which contains topics like using their internal APIs. Very smooth process, they interview in batches.

Was an interesting experience. Its a 3 hour coding challenge where you are working on one question. Its unlike other interviews where they are hackerrank based. I couldnt figure out the bug as there are no specific test cases that can trigger you to think of what can be wrong. I felt it was a very practical interview. I did not get through to future rounds.