How should a startup choose its tech stack?

There is no "best" stack. There's a best stack for your specific situation. The right question isn't "what's the best technology?" It's "what are our constraints?"

Business constraints determine the stack, not personal preference. One client uses Firebase as core. Another uses Google Cloud without Firebase. Another hosted AI models on Azure because they had $30K in Microsoft startup program credits. Credits, existing team, compliance requirements — these are the real inputs.

Every developer has a default stack where they have deepest expertise. Deviations from that default are fine, but they cost efficiency and depth. The handbook calls this "vector distance from default stack." When evaluating a developer, ask: "What's your default stack, and how far are we from it?"

Context Over Purity says business constraints trump technical purity — bias toward fewer services and integrations. Default Stack says deep expertise in familiar tools beats starting fresh each time. Consolidation warns that every service added is another failure point — one good platform beats five specialized ones.

Before asking "what's the best stack?" ask:

• What team or expertise do we already have?
• What cloud credits or existing infrastructure do we have?
• What compliance requirements matter?
• What does our developer know best?

If you have no constraints and no team, pick a developer with a proven default stack and use theirs.