What problems is Pantheon solving and how is that benefiting you?
We have a single code-base that is used to power hundreds of sites. We needed a hosting partner that could support being able to make a single update in this codebase and in a single update with a development crew of three people (two front-end developers and one back-end) push this out to all hundreds of these sites. From the get go, I was able to transfer all these sites from the previous hosting environment to Pantheon in a single day. This did require an on-ramp of about three months to develop the custom scripting but the actual work took less than a day. Updating DNS took a little longer as anticipated; however, in Pantheon with Terminus we've greatly integrated GitHub Actions for a solid ci/cd pipeline that is bulletproof.
We run through cypress testing, linting and Drupal Code standards before the code is even pushed to Dev. We have up to 10 open pull requests at any time where we can go to our canary sites and test with live data. Then we we go to publish a release we use Autopilot to for visual regression testing. We're no longer debugging build issues at the time of release as these are all ironed out before the code even makes it to multidev. I calculated this out to about 52 hours I personally get back every year. This allows us to add additional safe-guards.
For example, we have one chunk of code that always requires a database update if our front-end devs touch it. They always forget, so we now have an additional check in GitHub to make sure if those files are checked that additional approvals are needed. I would not have had this time to develop these extra tools in our previous host.
Additionally, I have further developed out local development processes to be more streamlined with this added time such as adding hash checks to see if we really need a composer build or theme build when merging in other work. With the guardrails that Pantheon puts in place that standardizes how builds should be once you crack your pipeline you can focus on building the tools that will help you build more with less. Review collected by and hosted on G2.com.