A recruiter looked at my LinkedIn profile and contacted me there. Got first phone interview setup with two interviewers. Interview was setup for a week after. - Started with asking about my present job. Team details and work specifications. - Went to collabedit.com for technical questions. Q1: Given a string, return true if it is a number else return false. (Pretty straightforward) Q2: What is a singleton class and how would you design it. Some threading related things for it. Q3: Write a parseInt function (Similar to Q1). I answered all the questions nicely. No objections. Since I looked referred glassdoor for practice, I was familiar with all these questions. How can I get them wrong ?!?! But still got a REJECTION. No reasoning given. They told, they find me a potential candidate but cannot go ahead for now.