I was interested in Booking.com because I have relevant experience in developing booking systems.

I had my first interview with HR for basic information.

After a few weeks, I got another one with two team leads via Skype, using Titanpad to share coding skills.

Regarding the delay, it seems they are extremely busy.

They said that the interview should normally not take more than 45 minutes.

After introducing ourselves, they started asking some tech questions.

I'd expected to hear questions about data structures, algorithms, problem-solving tasks, maybe some "brain teasers," or other simple math problems.

They proposed I code a function in pseudocode to get a shortened version of a description, but to keep whole words in the sentence and not cut them.

After that, they asked questions about each line and proposed I improve my two lines of code to make it faster.

They tried to "tip" me using caching there.

Anyway, it looks like that was enough for them to understand something about me, which caused them to reject my application with a general explanation that I do not have deep knowledge in the area they needed.