Hi… For development, a single node is fine, but I think you might be misunderstanding the full reasons for having multiple nodes in production:
Having said that, paring down 3 → 1 for the time being, while you are still just testing, might be possible, depending on which database you’re actually using. Plausible ones that come to mind include Fly Postgres (a.k.a. “Legacy Postgres”), Fly MPG, MySQL…
The Fly Postgres clusters in particular are a big responsibility, like owning a pony or something, 
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