1 phone interview (coding) + 3 rounds face 2 face, took about 2 weeks. Questions are all easy, can be found in leetcode. However, there are some tough behavior questions regarding your career plan. I also asked how they made money and seems they had no idea about their future. Besides, the work they are doing everyday seems boring: use search engine APIs to support more market places, localization, etc. I asked what's the most challenging work they face, and they told me to support more ad websites, support foreign websites, etc. So basically their future work is to enhance the existing product to support more ad site in global regions.