I applied through ARM website and received communication within a month.
First round was a telephonic screening. It involved basic questions related to VLSI Layout, Scripting, Current projects and work experience.
I got invitation for an onsite interview within a week of telephonic interview.
There were 4 one-to-one interviews. Most of the questions were fundamentals of VLSI like, operation of inverter, timing analysis, logical effort, performance, SRAMs, Euler Paths, Transistor level schematic, layout - comparison of different input ordering based on performance, transistor folding and stack folding.
Finally there was a conversation with HR to wind up the entire process.
They gave me their response the next day.