Baseten just closed a $1.5 billion raise at a $13 billion valuation — a monster round for a company most people outside AI infrastructure have never heard of. The California-based startup, co-founded by Australians, sells software and computing infrastructure that lets companies customize their own AI models without feeding data to OpenAI or Anthropic. Revenue has grown 20-fold in the past year, driven by surging demand for "inference" — the phase where trained AI...