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Comment by Nextgrid | Hacker News Reader

Which is what always happens when the company aims to build an "engineering playground" full of microservices and other moving parts without a clear technical justification and balancing the pros & cons and why I personally don't like working on such projects - it makes me feel uneasy not having a good understanding of the entire system.

To be fair to Slack, at their scale, lots of moving parts might make sense, but I see a lot of companies (including startups with very few customers) going down the microservices route and exposing themselves to such a risk when there is no major upside beyond giving engineers lots of toys to play with and slapping the "microservices" and related buzzwords on their careers page.

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I think you are drawing the wrong conclusions here... Microservices is not the boogyman here. It more likely has to do with speed of development, developer turnover and a plethora of other things that result in insufficient knowledge transfer.

Microservices (like just about anything) can be implemented well or poorly. There's a reason we have sophisticated orchestration solutions like Kubernetes... it exists to tame large scale deployments that has sensible failover processes.

The benefits you get are services that can be scaled independently, deployments that only affect isolated pieces of code, horizontal scaling, dockerized environemnts, etc. All of these advantages should exist in well designed systems, but systems that have been executed hastily will likely have critical problems crop up at some point.

Did you mean boogeyman? https://www.dictionary.com/browse/boogeyman

Obviously he means boogeyman. Even on your page, it suggests another spelling. What a useless comment.

I think that all other things considered equal, a microservices architecture has more moving parts and is more complex to learn than a monolith. The same applies for Kubernetes, it's one extra layer of abstraction and moving parts that you need to understand and keep into account when developing or making changes to an existing system.

I am not saying that microservices is a problem for Slack (at their scale it can make sense), but I am expressing my overall concern about smaller companies going down the same route when their scale or the problem being solved doesn't justify it and they end up having to deal with the (self-inflicted) problems of a massively distributed system with no major upside as well as my personal opinion of why I feel uneasy working on systems where I don't have a full overview of how it works and its potential failure modes.

When it comes to the benefits of microservices I am not sure whether those are all worthwhile considering the overhead and extra complexity of development on a microservices architecture.

In a monolithic application, most data and functions you might need are just a function call away and you typically have one or a handful of databases to interact with, often abstracted away by an ORM. In a microservices architecture, you suddenly need to worry about serialization, authentication and communication between services (and its failure modes, etc) and might require coordinated changes across several services, each of which might use a different language/framework and deployment process.

In terms of getting started, it has always been easier for me to work on a monolith where the codebase makes up for bad/no documentation because my IDE can resolve the majority of the symbols and allows me to see where the data I need lives and where it's being used. In a microservices architecture all of that goes out the window and you need to do a lot more manual "discovery" work searching through the documentation (if there is documentation, which is not a given) and manually figuring out the RPC calls because IDEs typically can't resolve cross-service communications.

Running a monolithic application locally is a lot easier than a microservices architecture. For the former you can typically get away with just a database and cache server all running natively. The latter pretty much imposes a container-based stack where you are now running 10 databases, caches, reverse proxies and everything involved around service discovery, which adds yet another layer of abstraction and makes you spend more time on this useless plumbing than actually getting work done and delivering business value.

I like your statement but I don't think it has to do with the speed of development either.

In a monolithic architecture the devs that deal with it, have to deal with the program as a whole. So if something doesn't work, its their problem. Where as in a micro service architecture it can be easy to spin up a service and not know the systems that integrate with it.

The problem here is with documentation and understanding of architecture. Its just the nature of the beast that the monolithic dev knows how thing communicate with the monolithic program because he needs to know, in order to do his job. In this instance the problem isn't with micro services, its with the execution. And that execution is a very easy trap to fall into with micro services.

The same thing can happen in a monolith. Make a change, run tests, and make sure your new feature works, while breaking some untested behavior you didn't know about in some other part of the monolith.

Kubernetes is for scaling, the microservice complexity is about the spaghetti relation graph between them, the mis-consistency effects and so on. Believe me, you better have a infrastructure/development process that justify them.

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