I had applied for an SDET position, and even after some rounds of interviews, I was not asked anything about software testing. I was asked to design and develop stuff. At some point, I was wondering if I had applied for some design or development role.

@recruiters: Kindly mention in the job description that candidates would be asked to design and develop software. The job description was totally different from what was asked in the interview.

You have a client-server architecture. In between the client and server, you have your application. Given each server has a success probability factor x (0 to 1), you are supposed to come up with logic to decide which server among all active servers would process your request and give back the response to your application, which in turn is displayed to the user. Design and develop your application logic after that.