docs(best-practices): update size your env guide

[afgambin]

Description

This PR addresses the documentation efforts of this epic.

It updates the Size your environment guide, and adds information from internal docs, covering what we test, how we test, setup, and results.

When should this change go live?

• This is a bug fix, security concern, or something that needs urgent release support. (add bug or support label)
• This is already available but undocumented and should be released within a week. (add available & undocumented label)
• This is on a specific schedule and the assignee will coordinate a release with the Documentation team. (create draft PR and/or add hold label)
• This is part of a scheduled alpha or minor. (add alpha or minor label)
• There is no urgency with this change (add low prio label)

PR Checklist

• The commit history of this PR is cleaned up, using {type}(scope): {description} commit message(s)

• My changes are for an upcoming minor release and are in the /docs directory (version 8.9).
• My changes are for an already released minor and are in a /versioned_docs directory.

• I added a DRI, team, or delegate as a reviewer for technical accuracy and grammar/style:
  • Engineering team review
  • Technical writer review via @camunda/tech-writers unless working with an embedded writer.

[github-actions]

👋 🤖 🤔 Hello, @afgambin! Did you make your changes in all the right places?

These files were changed only in docs/. You might want to duplicate these changes in versioned_docs/version-8.8/.

• docs/components/best-practices/architecture/sizing-your-environment.md
• docs/components/best-practices/architecture/test-your-environment.md

You may have done this intentionally, but we wanted to point it out in case you didn't. You can read more about the versioning within our docs in our documentation guidelines.

[github-actions]

The preview environment relating to the commit 12d2bff has successfully been deployed. You can access it at https://preview.docs.camunda.cloud/pr-7839/

[afgambin]

Hi @ChrisKujawa, @felix-mueller ,

I’ve started working on this. A few comments/questions:

1. I’ve done an editorial pass on the Size your environment guide. I understand it as a best practices guide that explains the concepts needed to size an environment. The structure looks good now, but many parts and some of the data seem outdated (as mentioned). Updating those sections would require input I don’t currently have.

2. The related GitHub epic mentions the goal of documenting more of the testing aspects based on the internal reliability testing docs. It’s not fully clear to me what the desired outcome is. Possible options:
   a. Do we want to document how our testing is done in a public-facing way (i.e., by adapting the internal doc into a public guide)?
   b. Do we want to explain how customers can run these tests themselves?
   c. Or both, i.e., documenting what/how our testing is done, and how customers can replicate it?

From my perspective, it might make sense to split this into two guides:
i) A sizing best practices guide focused on concepts (already existing): This would not need frequent updates and would contain few numbers/data.
ii) A separate guide focused on testing. Long term, this would ideally be kept automatically up to date, including example data and test results.

Feedback would help clarify how to proceed from my side. For the up-to-date numbers and content, I would need a review pass from your side, once we have those up to date testing numbers.

P.D.: I added a Test your environment guide, just as a draft, based on the internal doc.

Thanks!