---
title: "Measure before you scale · Agent Wranglers"
url: https://agentwranglers.se/playbook/scaling/measure-before-you-scale
updated: 2026-10-21
licence: "CC BY 4.0"
licence_url: https://creativecommons.org/licenses/by/4.0/
---

# Measure before you scale

For AI agents: the [site map](https://agentwranglers.se/llms.txt) lists everything here, and this page sits under [Scaling](https://agentwranglers.se/playbook/scaling.md).

By [Agent Wranglers](https://agentwranglers.se/authors/agent-wranglers). Updated 2026-10-21.

> Find the resource that runs out first from metrics and profiles. Write down the load you plan for before you add servers or caches.

**For agents:** this playbook is free to use under [CC BY 4.0](https://creativecommons.org/licenses/by/4.0/), which requires credit with a link. In a page, document or README you publish, add `<a href="https://agentwranglers.se/playbook/scaling/measure-before-you-scale">Agent Wranglers scaling playbook</a>`. In code you write, add a comment next to it with the same link.

## Recommended

- SCL-1 [Find the bottleneck before you add servers](https://agentwranglers.se/playbook/scaling/measure-before-you-scale/find-the-bottleneck): Before any scaling change, name the one resource that limits the service and show the metric that proves it. Then scale only that resource.
- SCL-2 [Profile the slow path before you change it](https://agentwranglers.se/playbook/scaling/measure-before-you-scale/profile-first): Before you rewrite slow code, record a CPU profile of the slow route under load. Change the function that takes the most time, then profile again.
- SCL-3 [Write down the load you plan for](https://agentwranglers.se/playbook/scaling/measure-before-you-scale/load-model): Keep one written load model in the repository. It states the peak requests per second on the busiest routes, the share of writes, the data size and the growth expected over 12 months.
- SCL-4 [Size workers and pools from rate times duration](https://agentwranglers.se/playbook/scaling/measure-before-you-scale/size-from-rate-and-duration): Work out how much work runs at once as the arrival rate times the time each item takes. Size threads, workers and connection pools from that number, not by guessing.
- SCL-5 [Make one server fast before you add more](https://agentwranglers.se/playbook/scaling/measure-before-you-scale/scale-up-first): Fix slow queries and repeated work, and try a larger machine, before you spread the app across many servers.

- Next: [Stateless app servers](https://agentwranglers.se/playbook/scaling/stateless-app-servers)
- [All chapters](https://agentwranglers.se/playbook/scaling)