Nuance Senior Software Development Engineer interview questions

I got call from recruiter for interview at Nuance Pune. It started with spring objective test, followed by java programming test of about hour. Program was supposed to be production ready code, including junits and should run in multi-threaded environment. After that technical interview with the team lead, followed by technical architect, and product manager. And finally with head of engineering and Hr head. It was long process. I was also given one poc in between. Overall process was lengthy but smooth and well managed. Interview was fully technical and one of the toughest i ever faced.