When Not to Do Microservices: A Reality Check
Let's talk about why microservices might be the worst decision you'll make for your architecture. Yeah, I said it.
Everyone's jumping on the microservices bandwagon like it's 2016 and Netflix just open-sourced Hystrix. But here's the thing: most teams are shooting themselves in the foot, and they don't even realize it until they're drowning in network timeouts and distributed transaction hell.
The Latency Thing Nobody Wants to Talk About
Here's the #1 mistake I see everywhere: teams completely ignore that every network call is a tax on performance. They take a function that runs in nanoseconds and split it across three services, adding 10-20ms of latency, then wonder why their app feels sluggish.
Let me put this in perspective: your CPU can execute literally billions of instructions in the time it takes to make one network call. BILLIONS. Those "few milliseconds" of network latency? That's an eternity in CPU time. It's like asking Usain Bolt to run a race but making him stop and tie his shoes between every step.
I've seen teams take a perfectly fine checkout process that ran in 50ms and turn it into a distributed mess that takes 200ms. Why? Because someone read a blog post about how Amazon does microservices. News flash: you're not Amazon.
When Microservices Will Ruin Your Life
Your Code is Actually Coupled (Be Honest)
If your services are constantly chatting with each other to get anything done, you don't have microservices. You have a distributed monolith with extra steps. Can your service do its job without talking to another service for at least a few seconds? No? Then keep it in the same process.
I worked with a team that split their trading platform into microservices. Every trade needed to check balance, validate limits, update positions, and record transactions. They went from sub-millisecond trades to 50ms. In high-frequency trading, that's the difference between making money and losing your shirt.
You're Under 10 Engineers
Small teams doing microservices is like a startup buying a warehouse before they have inventory. You'll spend all your time on DevOps instead of building features.
I mean it: if you have fewer than 10 engineers, you're going to spend more time debugging service mesh issues than solving customer problems. Your standups will turn into "why is the service discovery broken again?" sessions.
Your State Management is a Nightmare
The moment you need distributed transactions, you should pause and reconsider. Seriously. Managing state across services is where good engineers go to cry.
Example: An inventory system where you need to keep stock counts, reservations, and orders in sync. In a monolith? It's a database transaction. In microservices? Welcome to the saga pattern, eventual consistency, and customers occasionally buying products that don't exist.
The Architecture Ladder (Pick Your Fighter)
Instead of going full microservices because it's trendy, here's how to actually think about it:
Just Use a Monolith (<1ms latency) Start here. I'm serious. Unless you have a damn good reason, just build a monolith. It's fast, simple, and you can actually debug it without a PhD in distributed systems. Perfect for startups, MVPs, and honestly, most companies.
Modular Monolith (<1ms latency, but organized) This is the sweet spot for growing teams. Same process, but with clear boundaries. It's like having roommates with separate bedrooms but sharing a kitchen. You can always split later if needed, but right now, you're not paying for multiple apartments.
Service-Oriented Architecture (5-50ms latency) When you actually have distinct business units that rarely talk to each other. Think billing service, email service: stuff that can fail without taking down your whole app. This is microservices for adults who understand trade-offs.
Microservices (10-100ms+ latency, pray for your soul) Only worth it when you have:
50+ engineers who need to deploy independently
Services that genuinely don't need to talk to each other
Different scaling needs (like that one report that kills your database)
The budget for a platform team
Serverless (50-500ms+ latency, hope you're not in a hurry) Great for cron jobs and webhooks. Terrible for anything that needs to be fast. Cold starts are real, and they will hurt you.
How to Migrate Without Destroying Everything
Okay, so maybe you actually need microservices. Here's how not to screw it up:
1. Start with a Modular Monolith Get your boundaries right while everything's still in one process. It's way easier to refactor a module than to merge services back together (trust me, I've done both).
2. Measure First, Cut Later Is something actually slow? Prove it with data. "It might scale better" is not a reason to add 30ms of latency to every request.
3. Extract the Boring Stuff First Start with email notifications or report generation: stuff that can fail without taking down your app. Learn how to operate services with training wheels on.
4. Build the Damn Infrastructure First You need:
Service discovery that actually works
Logging that doesn't make you want to quit
Tracing so you can figure out WTF is slow
Circuit breakers so one bad service doesn't kill everything
If you don't have these, you're not ready for microservices.
5. One Service at a Time Don't go extracting five services in a sprint. Extract one, run it for a month, learn what broke, fix it, then maybe extract another.
The Real Talk
Look, microservices aren't evil. But they're not magic either. Every network call is a decision to trade simplicity for modularity. Sometimes that's worth it. Usually, it's not.
Ask yourself:
Can this wait a few seconds? (If no, probably keep it together)
Do we have 10+ engineers? (If no, definitely keep it together)
Are we solving an actual problem or just résumé-driven development?
Most importantly: those few milliseconds of latency aren't just numbers. They're the difference between a snappy app and one that feels like it's running through molasses. In CPU time, milliseconds are geological eras.
Start with a monolith. Organize it well. Extract services when you have real pain, not imaginary future pain. And for the love of all that is holy, measure your latency before and after.
Your users care about speed, not your architecture diagrams.