How to Run an Old Laptop as a Server — Without It Sleeping on You
A spare laptop makes a fine always-on machine. The reason it keeps dying isn't the hardware — it's three power defaults written for a device someone carries, not one that lives on a shelf.
Your Postgres Connection Limit Is Not Your Concurrency Limit
A database that accepts a hundred connections is not a database that does useful work on a hundred things at once. On a four-core box, throughput stopped scaling at four — and the fix was to stop counting connections and start counting cores.