How I built multi-model LLM routing on Groq's free tier

I hit Groq's token limits building an AI research paper analyser. Here's the routing system I built to get around it — and why it made the app better. I didn't plan to build a multi-model routing system. I was just trying to summarise a 40-page research paper without paying for an API. That's how Papers.ai started — a side project born out of frustration with how painful academic literature reviews are. You open a paper, it's 30 pages of dense methodology, and you spend 20 minutes just figuring