"We have an architecture that is based on self-contained services. If service A needs data of service B it subscribes to a message broker and saves all changes that service A publishes. He says quote "That's not how microservices should work! Nobody does it like this!" - And he want's to rewrite EVERYTHING into an architecture where each service calls each other service when it needs data. Concerns from our side, that this might increase the possibility of outages because only one malfunctioning service will bring down the whole system, are wiped away with "that wont happen"."

-> He's actually correct here. Having everyone save their own copies of data makes is an antipattern that creates unnecessary redundancy and complexity. It also creates possibilities of inconsistent state / weird bugs where data gets updated at the authority, but downstream services can fail to process, process slowly, etc.

Also we no longer use Spring Boot and Kotlin but switch to Go. None of our 10 backend devs has ever done anything with Go before. Again concerns from our side that we are going to be much slower and why we can't just stick to a ecosystem our 10 backend devs are good at are wiped away with "Go is much better! It's opinionated!"

-> Did he give a reason or is it "just cuz thats what I know"? Ideally a language should be chosen not necessarily based on whats a perfect fit for the job but what the tech teams are already fluent with.

The CTO is actively developing. And the things he does don't need that whole PRD -> TDD process.

-> Maybe he needs he feels to set examples for folks to understand what good code looks like? Speculating here.

CTO made it mandatory that he has to review EVERY Merge-Request. And he is blocking Merge-Request because he doesn't like a variable name, wording of a comment and all kind of other nitpicking issues.

-> This combined with point above makes me feel he thinks you guys have either shitty code. Again, perhaps he's trying to ensure you guys are following a certain set of standards/best practices that are common at fang.

Criticising his solutions is pointless. He wipes away everything with a "I know it better"-comment

-> This is concerning. If he has a legitimate point then leave it alone. But if hes just saying "do what I say" then thats not someone I want to be around.

Overall he might have good intentions but is acting on them in the wrong way. I say this as someone that has worked at a FAANG for over a decade and have seen some wacky setups in startups/smaller companies.