To me it sounds like so: "We realized that we were not running microservice architecture, but rather a distributed monolith, so it made sense to make it a regular monolith". It's a decision I would wholeheartedly agree with.
This meant that it was costly to maintain and caused a lot of confusion, especially with internal dependencies (shared libraries): this is the trade-off they did not like and wanted to move away from.
They moved away from this in multiple steps, first one of those being making it a "distributed monolith" (as per your implied definition) by putting services in a monorepo and then making them use the same dependency versions (before finally making them a single service too).
> When pressed for time, engineers would only include the updated versions of these libraries on a single destination’s codebase.
> Over time, the versions of these shared libraries began to diverge across the different destination codebases.
> ...
> Eventually, all of them were using different versions of these shared libraries.> We no longer had to deploy 140+ services for a change to one of the shared libraries.
Taken in isolation, that is a strong indicator that they were indeed running a distributed monolith.
However, the blog post earlier on said that different microservices were using different versions of the library. If that was actually true, then they would never have to deploy all 140+ of their services in response to a single change in their shared library.
Your runtime version is out of date / end of life. You now need to update and deploy all 140 (or at least all the ones that use the same tech stack).
No matter how you slice it, there are always dependencies across all services because there are standards in the environment in which they operate, and there are always going to be situations where you have to redeploy everything or large swaths of things.
Microservices aren’t a panacea. They just let you delay the inevitable but there is gonna be a point where you’re forced to comply with a standard somewhere that changes in a way that services must be updated. A lot of teams use shared libraries for this functionality.
... otherwise you'd have to do something silly like update every service every time that library changed.
> Eventually, all of them were using different versions of these shared libraries.
> Eventually, all of them were using different versions of these shared libraries.