Build times are long for large sites

[LoneRifle]

Due to the single-threaded nature of Ruby, Jekyll builds are less viable for sites of potentially thousands of pages. This is a problem for Netlify, which imposes a strict 15 minute build time limit on preview builds, which in turn gate pull requests.

This can have significant impact for sites which requires content to be updated immediately

Jekyll 4 resources:
https://jekyllrb.com/docs/upgrading/3-to-4/
https://github.com/github/pages-gem#list-dependency-versions

[LoneRifle]

Possible approaches:

• Parallelism - allow sections of a site to be built in parallel. May require that we use a build script for all Isomer sites, which would dovetail with centralising of CSP, Gemfiles, etc
• Jekyll 4, which features performance improvements with buildtime template caches

[lisa-kwok]

To add on to this thread. We've explored the user of Amplify but still did not manage to get incremental builds to work

[lisa-kwok]

Have migrated GoBusiness to Amplify

[LoneRifle]

Moved GoBusiness back to Netlify pending investigation of unresponsiveness to GitHub webhook notifications

[LoneRifle]

Profiling of the large sites show that the lion's share of the time is spent generating breadcrumbs. Liquid is known to struggle with iterative loops, which is being used extensively in the relevant part of the template