The AI provider landscape changed twice in one week. On April 28 , OpenAI ended its exclusivity arrangement with Microsoft and announced expanded availability on AWS. On May 4 , AWS made it concrete: GPT-5.5 and GPT-5.4 are now available through Amazon Bedrock in limited preview, Codex is on Bedrock as a CLI, desktop app, and VS Code extension, and a new Bedrock Managed Agents product wraps OpenAI's frontier models with AWS infrastructure for production agent workflows. That's the news cycle. Here's the founder version: if you've been building an AI SaaS on the assumption that "OpenAI = Azure" and "Anthropic = AWS" — those defaults no longer hold. Both frontier providers now sit on AWS. Both also sit elsewhere. Your provider decisions just got more interesting and harder. This post is about how to think through that, not which "winner" to pick.…