1. Your 100 users/min may also be put across as 300 req/min.
2. Try startups that are going from 10 req/s to 100 req/s rather than directly approaching large, massively distributed backends.
3. To seriously qualify for these you also need the skill sets. Experience with centralized logging, multi area-zone data-centers, deploying at scale, configuration management, advanced version control workflows, deeper understanding of protocols, caching, awareness of security pitfalls, knowledge of GNU/Linux internals etc will certainly help.
4. Even in the absence of much production experience, you can significantly lower their concerns by demonstrating working knowlege in multiple of these above mentioned skill sets.
Also, take a look at https://github.com/cjbarber/ToolsOfTheTrade.