Synchronous calls to slow services on busy paths hold threads and whole machines while nothing happens. To keep up, teams add servers that also mostly wait.
The fix you can use today
Use async I/O for network and disk calls on busy paths.
Move slow, non-urgent work to a queue and a background worker.
Match the concurrency model to the work: async for I/O-bound, processes for CPU-bound.
GreenCode researchers list blocking calls on busy code paths as an energy waste to fix.
Tools that help
GreenCode Constitution skill (GreenCode researchers): open-source energy principles and a catalogue of 37 energy anti-patterns that an AI coding agent can follow to find and fix waste like this
Scaphandre: measures the power drawn by each process on a Linux server and exports it to Prometheus and other monitoring stacks
How GreenCode helps
GreenCode helps tackle this by generating a load test from your system's own endpoints. It records energy as well as speed while it runs, and ranks the hotspots by the energy they use. More on this.
