Started off with a face-to-face interview in their office, where we discussed the business, architecture, etc. The initial interview was very friendly and positive.

Then had to do a coding exercise, the N-Way associative set cache business. There was no time limit attached, however, two things you must do:

• Read the question (and question title). Look up the concept. Mimic all the hardware components involved. Building your own interpretation that offers the same functionality will not do.
• Take into account that they want a solution that is performant and scalable in a high-traffic environment. They do not tell you this, which leads to asking tons of questions. Make no assumptions about anything. The initial requirements are so light on that they should be welcoming and answering all questions (I'm pretty sure that is their directive), e.g., "What is production ready?", "Please explain the desired architecture?", "How will this component be used in production systems?" It might feel stupid to ask, but even stupider to have missed the opportunity because you didn't ask.
• Be patient. I had set an artificial deadline on myself and would have benefited by taking time to rethink my assumptions and test the solution more intensively.

*I did actually ask this question but gave up waiting for an answer (see (d)).

N-Way associative set cache