The hiring process is wonderful. The first round was an online coding round of 4-5 hours where you will have to implement a problem (a simple cross-browser game in my case) using HTML, CSS and vanilla JavaScript. Next was a phone screen where I was asked two questions--one related to front end (JavaScript) and the other related to algorithm and data structure, After this I got a call to attend the onsite interview at their Bangalore office. Being an outstation candidate, I was flown over to Bangalore--this is the best part, Flipkart will book your two-way flight tickets, hotel (with free breakfast) and cab to and from the airport. This is unlike most other organizations that ask you arrange for travel and accommodation yourself and reimburse the expenses later; Flipkart will take care of everything and all you have to do is sign a few papers and feel like a king.
The onsite interview consisted of four rounds (greatly involving the whiteboard):
1. Problem solving round: this was mostly based on algorithms, data structures and design but relevant to the profile I had applied for. I had to provide a solution in the context of HTML, CSS and JavaScript; I was asked to implement a simple interactve game in this round.
2 & 3. Technical round on HTML5, CSS3 and javascript This involved questions on advanced concepts of front end web development and JavaScript in particular. Had to create lots of reusable plugins using JavaScript.
4. Hiring Manager Round: This final round was with the hiring manager where I had to answer a few technical questions but mostly this round was to check my cultural fit in the organization. Questions relating to my work, experience, aspirations and interests were asked.
Overall, I would say the entire interview process is not easy, but not very difficult either. You should really know your JavaScript pretty well, brush up the common algo+DS and you'll manage just fine. Moreover, you will enjoy the experience greatly.
I got the offer the next day itself! :-)