[bingo_cannon]

IMO, the companies that deal with large distributed systems don't always look for experience in the field. The interview focus more on fundamentals (time complexity etc) if you they are hiring for a junior/mid level. So the plan of action would be to button down the basics and apply to these companies.

For experience, you can run your simple client-server setups against a traffic generator e.g. apache bench. Try out different things to achieve maximum throughput.