How Macy watches your world without draining anything

Watches are standing queries

When you tell Macy to watch NVDA for a five percent move, that sentence becomes a standing query on our servers, not a timer on your phone. Your battery is not involved. Connected apps stream changes to Macy through their own APIs, and each change is evaluated against your active watches in one pass.

The hard part is silence

Detecting events is easy. Deciding not to text you is the hard part. A stock crosses your threshold, wobbles back, crosses again. Naive systems text you three times. Macy debounces, dedupes, and holds a small memory of what she already told you, so a single real event produces a single message.

We measure the health of the system by a number most products would find strange: messages per user per day. If it climbs too high, something is wrong. The goal is not more alerts. It is fewer, better ones.

Why this needs a server at all

A phone that is asleep cannot watch anything. A server can hold ten thousand standing queries for the price of a coffee. The architecture follows from the promise: she watches so you do not have to.