Wayfair Developer interview questions

Step 1: Spoke with recruiter. She asked me about prior projects, technologies that I've worked with, previous salary, desired salary, etc. Step 2: Phone interview with Software Engineer II. He asked me four main questions. 1) What's the benefit of using a Web Service instead of SQL directly in client side code. 2) Given a singly linked list, swap the element at position k with the element k nodes from the end. 3) What are the different SQL Joins. 4) Write an SQL query. Ultimately, i didn't have enough database experience to move onto the next round.