[$500] [HOLD for payment 2024-03-07] [Performance] Use Intl Collator instead of the string localeCompare

[mountiny]

Coming from Slack

### Problem
Lots of app critical metrics (TTI, input delay etc.) are hindered because of weak performance inside Prototype.string.localeCompare function in Hermes engine.

### Solution
Based on Hur's investigations, we can improve performance by swapping out localeCompare with Intl.Collator implementation.

More details are available in the linked analysis issue.

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• Upwork Job URL: https://www.upwork.com/jobs/~01af6fd0b61753f3bb
• Upwork Job ID: 1765747002690428928
• Last Price Increase: 2024-03-07

[kacper-mikolajczak]

Hi @mountiny 👋

[mountiny]

Follow up from the PR:

• create uni tests for the new util libs
• create a plan to remove the string.localeCompare from other parts of the app

@kacper-mikolajczak would look into this tomorrow

[kacper-mikolajczak]

create uni tests for the new util libs

PR for tests: #36879

create a plan to remove the string.localeCompare from other parts of the app

With this, I will wait till we have 100% sure that there are no regressions and actual performance gains in the app. What do you think @mountiny ?

[mountiny]

I will wait till we have 100% sure that there are no regressions and actual performance gains in the app

We can wait a bit, we saw that there are performance gains in the tests and your analysis. How do you want to measure that there are some improvements thanks to this?

[kacper-mikolajczak]

We can wait a bit, we saw that there are performance gains in the tests and your analysis.

If that is enough of evidence, we can swap out other occurrences as well (additionally ensuring that we don't introduce any regressions). I can prepare PR for that 👍

How do you want to measure that there are some improvements thanks to this?

The next phase of the audit (Control phase) will add specific metrics and perf tests to keep the performance at stable level.

[mountiny]

The next phase of the audit (Control phase) will add specific metrics and perf tests to keep the performance at stable level.

Yeha I dont think we would want to wait this long for that

[adhorodyski]

@mountiny Agree, we should integrate this right away. I'm OOO tomorrow but we'll sync up internally on how to address this! It definitely needs to stay in check, this function runs ~250k times during the startup if I recall correctly :)

[hoangzinh]

@mountiny the PR has been deployed to Prod since last week. Could you help to add Bug label or Feature so a BZ member can be added to process payment? Thanks

[melvin-bot]

Triggered auto assignment to @zanyrenney (NewFeature), see https://stackoverflowteams.com/c/expensify/questions/14418#:~:text=BugZero%20process%20steps%20for%20feature%20requests for more details.

[melvin-bot]

Job added to Upwork: https://www.upwork.com/jobs/~01af6fd0b61753f3bb

[melvin-bot]

Current assignee @hoangzinh is eligible for the External assigner, not assigning anyone new.

[mountiny]

@zanyrenney this is ready for payment $500 to @hoangzinh

[zanyrenney]

please apply to the job on upwork @hoangzinh

[hoangzinh]

Applied. Thanks @mountiny @zanyrenney

[zanyrenney]

sent offer

[hoangzinh]

Accepted. Thanks @zanyrenney

[zanyrenney]

payment summary

paid $500 via upwork to @hoangzinh