Microservices are GREAT when 1 team owns each service. I haven't seen a good use case when you have 1 team supporting multiple microservices.
That's why I don't like the term "microservice", as it suggests each service should be very small. I don't think it's the case.
You can have a distributed system of multiple services of a decent size.
I know "services of a decent size" isn't as catchy as "go for one huge monolith!" or "microservices!" but that's the sensible way to approach things.
Even with a monorepo, you will hit a point where you have 1, 10, 100 million lines of e.g. Python, realize you should upgrade from 3.8 to 3.14 because it's EOL, and feel a lot of pain as you have to do a big-bang, all-at-once change, fixing every single breaking change, including from libraries which you also have to update. There's no way around this in current mainstream languages.
I don't think it's much better if you have to spend a year and a half updating 400+ different repos, though. It's much easier to use an operationalized language that knows backwards compatibility matters.
> I don't think it's much better if you have to spend a year and a half updating 400+ different repos, though.
There's two things going for separate services (which may or may not be separate repos; remember a single repo can have multiple services):
1. You can do it piecemeal. 90% of your services will be 15-minute changes: update versions in a few files, let automated tests run, it's good to go. The 10% that have deeper compatibility issues can be addressed separately without holding back the rest. You can't separate this if you have a single deployable artifact.
2. Complexity is superlinear with respect to lines of code. Upgrading a single 1mLOC service isn't 10x harder than updating ten 100kLOC services, it's more like 20, 30x harder. Obviously this is hard to measure, but there's a reason these massive legacy codebases get stuck on ancient versions of dependencies. (And a reason companies pay out the ass for Oracle's extended Java 8 support, which they still offer.)
I've worked on monoliths with 400+ developers that were great, but it takes skills that people who have only ever worked in orgs that mandate microservice just don't have.
Functional programming precludes encapsulation, so it doesn't scale indefinitely the way fractal paradigms can. Eventually, the complexity becomes overwhelming.
One effective solution to that is introducing microservices: programmers can still write entirely functional code, but have encapsulation in the form of services. They have to be micro, though, because conventionally-sized services are still big enough to strain the paradigm.
But I see junior engineers who aren't expected to think about the "architecture", by which they mean the modular design. They are handed a spec and they implement it, Mythical Man Month style. That treats organizing lines of code and organizing services as two completely-distinct activities, and depending on the company junior engineers are often not exposed to modular design until five or ten years into their careers.
Since when? Maybe we have different definitions of "encapsulation" but this clause seems nonsensical to me. FP is huge on encapsulation
Functional languages have some of the most rigorous module systems available. In fact Java adopted such a system recently, showing the weaknesses in its previous support for encapsulation via classes and packages.
Even if that state is kept outside the service itself (like a database or event queue) it can still be really hard to reason about when said state-stores are shared across a huge codebase. Changes to a part of the state can have negative effects in completely unrelated functionality.
And of course, there is nothing blocking a monolith from isolating/modularizing their state-stores, but it tends to not happen unless the architecture forces it to happen or through strong tech leadership.
If we try to read the commenter’s mind, at best they may have been talking about a hypothetical goal that no-one actually advocates.
The paranoid socialist in me thinks big companies like team-sized microservices because it lets them prevent workers from talking to each other without completely ruling out producing running software.
When companies instead encourage forums for communication across team boundaries, it unlocks completely different architectural patterns.
In high-uncertainty greenfield development, Explore projects or Lean Startup-style experimentation, having developer be close to the users they are serving is very efficient.
It also lets those companies reteam frequently, without needing to change the software to match the new team boundaries, which is very helpful when growing the team.
Even if you're using micro services, it's usually best to have them in the same repo organized into different directories.
No matter how many people you have, you really should minimize working on the same files concurrently. This is trivial with most languages
Why can the game industry etc somehow manage this fine, but the only place where it's actually possible to adapt this kind of artificial separation over the network, it's somehow impossible not do it beyond an even lower number of devs than for a large game? Suggests confirmation bias to me.
The main problem with microservices is that it's preemptive, split whatever you want when it makes sense after-the-fact, but to intentionally split everything up before-the-fact is madness.
How many times have AAA releases been total crap?
How many times have games been delayed by months or years?
How many times have games left off features like local LAN play, and instead implemented a 'microservice' as a service for online play?
How many times have the console manufactures said "Yea, actually you have the option of running a client server architecture with as many services you want?"
Comparing a game to almost any other piece of software, especially web based software, is how you end up with broken abstractions and bad analogies.
> How many times have games been delayed by months or years?
What are we arguing here? Because I can think of many microservice apps that are crap as well, and have no velocity in development.
> How many times have games left off features like local LAN play, and instead implemented a 'microservice' as a service for online play?
This is entirely irrelevant. We're talking about the trade-offs of separating networked services that could otherwise be one unit. You're saying "why do games have servers then" which is a befuddling question with an obvious answer.
That's like saying my web server is a Microservice because it's not run in my clients browser. It makes no sense.
Also those programmers seem to be neatly segregated in different areas of the project which I imagine work similarly to boundaries between the microservices at keeping the logic isolated between teams.
: I do AM surprised just how much QA people are credited in games, QA for major games sure do feel like an army.
The secret is that you're able to break a monolith apart, just like you can with microservices. You have APIs and modules of the monolith are responsible for their own thing. APIs are your contracts, just like in a microservice architecture.
The difference is that you can check if APIs are broken at compile time. In addition, you can view the API right in your IDE. In addition, your API isn't returning wishy-washy json with a half-assed OpenAPI spec - it's returning real types in a full-featured type system. And, cherry on top - you don't have to communicate over the network. Oh my god, you don't realize how many bugs and thousands of hours are wasted just working around that until you no longer have to. It's an immediate productivity boost.
But the best part is probably deployments. It's just so, so much more straightforward with one codebase.
The trouble comes when some political wind blows and reshuffles the org chart, and now you're responsible for some services that only made sense in the context of a political reality that no longer exists.
We have dozens of service components that are all largely independent of each other - combining them together would be purely a packaging decision, and wouldn’t really simplify much. In some cases, it wouldn’t make sense or even be possible at all.
An example is our execution agent, which executes customer workflows - that’s completely independent both conceptually and from a security perspective. Each agent instance executes a single flow at a time, for resource consumption and security reasons, which entails an ecosystem of services to manage that - messaging, data ingestion at scale (100K flows per day, multi-petabyte “hot” datastore for active data), orchestration, and other supporting services such as data access and network routing.
All of our teams support multiple services, and many of them qualify as microservices.
Rather than 1 micro service per team, which many devs.. it was some team that owns 20 services, generally way more services than developers.
It's probably just how non-lean Mag7 were in peak vs how lean most other orgs that try to ape them are.
The microservice team were especially terrible because the did all the initial work and basked in the "glory", but when it came to maintaining the services, they wanted nothing to do with it.
Sure a monolith that does 1000 things might not be ideal, but 100 repos for 100 micro services owned by a team of 5-10 devs is unmanageable on the other end of the spectrum. Oh and everyone forgets the orchestration layer.
1. when the requirements are better served by a different language/location/environment/platform.. or by deploying a 3rd party app.
2. some of the services need to quickly scale up and down, and you have enough traffic for it to be worth it.
3. if you have a tight SLA for parts of the app but not all of it.
The "one team per microservice" makes code-enclosure style code ownership possible, but it is the least efficient way I have ever seen software written.
I've long wanted to hack an IDE so people are only allowed to change the Java objects they created, and then put six Java programmers in a room and make them write an application, yelling back and forth across the room. "CAN YOU ADD A VERSION OF THAT METHOD THAT ACCEPTS THIS NEW CLASS?" "SURE THING! TRY THAT?"
People discount the costs of microservices because they makes management's job easier, especially when companies have adopted global promotion processes. But unless they are solving a real technical constriant, they are a shitty way to work as an engineer.