[HOLD for payment 2023-12-12] [CRITICAL] Optimize App Start Up Time with Lazy Loading

[muttmuure]

Problem

App is currently designed to load almost all of its code and resources in an eager manner, regardless of whether or not they are immediately needed. This results in unnecessary overhead and contributes to the slow boot time.

Solution

Implement lazy initialization techniques for resources like regular expressions that are not immediately required.

Lazy loading for large JSON files, notably emoji data, optimizes imports across the application.

#31776

Issue Owner

Current Issue Owner: @trjExpensify

[melvin-bot]

Triggered auto assignment to @johnmlee101, see https://stackoverflow.com/c/expensify/questions/7972 for more details.

[melvin-bot]

Triggered auto assignment to @MitchExpensify (Bug), see https://stackoverflow.com/c/expensify/questions/14418 for more details.

[melvin-bot]

Bug0 Triage Checklist (Main S/O)

• This "bug" occurs on a supported platform (ensure Platforms in OP are ✅)
• This bug is not a duplicate report (check E/App issues and #expensify-bugs)
  • If it is, comment with a link to the original report, close the issue and add any novel details to the original issue instead
• This bug is reproducible using the reproduction steps in the OP. S/O
  • If the reproduction steps are clear and you're unable to reproduce the bug, check with the reporter and QA first, then close the issue.
  • If the reproduction steps aren't clear and you determine the correct steps, please update the OP.
• This issue is filled out as thoroughly and clearly as possible
  • Pay special attention to the title, results, platforms where the bug occurs, and if the bug happens on staging/production.
• I have reviewed and subscribed to the linked Slack conversation to ensure Slack/Github stay in sync

[melvin-bot]

⚠️ Looks like this issue was linked to a Deploy Blocker here

If you are the assigned CME please investigate whether the linked PR caused a regression and leave a comment with the results.

If a regression has occurred and you are the assigned CM follow the instructions here.

If this regression could have been avoided please consider also proposing a recommendation to the PR checklist so that we can avoid it in the future.

[mountiny]

The regression is being handled

[melvin-bot]

Reviewing label has been removed, please complete the "BugZero Checklist".

[melvin-bot]

The solution for this issue has been 🚀 deployed to production 🚀 in version 1.4.7-4 and is now subject to a 7-day regression period 📆. Here is the list of pull requests that resolve this issue:

• Optimization of mobile startup time #31776

If no regressions arise, payment will be issued on 2023-12-12. 🎊

After the hold period is over and BZ checklist items are completed, please complete any of the applicable payments for this issue, and check them off once done.

• External issue reporter
• Contributor that fixed the issue
• Contributor+ that helped on the issue and/or PR

For reference, here are some details about the assignees on this issue:

• @situchan requires payment

[melvin-bot]

BugZero Checklist: The PR fixing this issue has been merged! The following checklist (instructions) will need to be completed before the issue can be closed:

• [@situchan] The PR that introduced the bug has been identified. Link to the PR:
• [@situchan] The offending PR has been commented on, pointing out the bug it caused and why, so the author and reviewers can learn from the mistake. Link to comment:
• [@situchan] A discussion in #expensify-bugs has been started about whether any other steps should be taken (e.g. updating the PR review checklist) in order to catch this type of bug sooner. Link to discussion:
• [@situchan] Determine if we should create a regression test for this bug.
• [@situchan] If we decide to create a regression test for the bug, please propose the regression test steps to ensure the same bug will not reach production again.
• [] Link the GH issue for creating/updating the regression test once above steps have been agreed upon:

[melvin-bot]

Triggered auto assignment to @trjExpensify (Bug), see https://stackoverflow.com/c/expensify/questions/14418 for more details.

[melvin-bot]

Bug0 Triage Checklist (Main S/O)

• This "bug" occurs on a supported platform (ensure Platforms in OP are ✅)
• This bug is not a duplicate report (check E/App issues and #expensify-bugs)
  • If it is, comment with a link to the original report, close the issue and add any novel details to the original issue instead
• This bug is reproducible using the reproduction steps in the OP. S/O
  • If the reproduction steps are clear and you're unable to reproduce the bug, check with the reporter and QA first, then close the issue.
  • If the reproduction steps aren't clear and you determine the correct steps, please update the OP.
• This issue is filled out as thoroughly and clearly as possible
  • Pay special attention to the title, results, platforms where the bug occurs, and if the bug happens on staging/production.
• I have reviewed and subscribed to the linked Slack conversation to ensure Slack/Github stay in sync

[mountiny]

This is ready for payment $500 to @situchan

[trjExpensify]

Cool, do we need a checklist?

[situchan]

Cool, do we need a checklist?

I don't think so

[trjExpensify]

Sent an offer here.

[trjExpensify]

Paid!