DEV Community

Cover image for 🔁 Throwback Thursday: That Time I Thought I Understood Microservices
Sumit Roy
Sumit Roy

Posted on

🔁 Throwback Thursday: That Time I Thought I Understood Microservices

#microservices #webdev

A cautionary tale of retries gone wild, broken assumptions, and what it really takes to build resilient microservices.

The Context

Fresh off reading about Netflix's architecture and armed with dangerous amounts of enthusiasm, I convinced our team to break up our "unwieldy" monolith.

The monolith? A perfectly functional Node.js app serving 50k users. But hey, microservices were the future, right?

What I Thought I Knew

"Microservices will solve everything!"

  • ✨ Independent deployments
  • ✨ Technology diversity
  • ✨ Team autonomy
  • ✨ Scalability nirvana

I had it all figured out. Split by business domains, add some Docker, sprinkle in Kubernetes, and boom - modern architecture!

The "Brilliant" Plan

Original monolith:

┌─────────────────┐
│   User Service  │
│   Auth Service  │  
│  Order Service  │
│Payment Service  │
└─────────────────┘
Enter fullscreen mode Exit fullscreen mode

My "improved" architecture:

┌──────────────┐    ┌──────────────┐
│ User Service │    │ Auth Service │
└──────────────┘    └──────────────┘
       │                    │
       └────────┬───────────┘
                │
┌──────────────┐    ┌──────────────┐
│Order Service │    │Payment Service│
└──────────────┘    └──────────────┘
Enter fullscreen mode Exit fullscreen mode

Four services, four databases, infinite possibilities for things to go wrong.

What Actually Happened

The Network Became My Enemy 

// Before: Simple function call
const user = getUserById(123);
const order = createOrder(user, items);

// After: Distributed nightmare
try {
  const user = await userService.getUser(123);
  const order = await orderService.create(user.id, items);
} catch (error) {
  // Which service failed? Who knows!
}
Enter fullscreen mode Exit fullscreen mode

Data Consistency? What's That? 

// The "simple" user registration flow
async function registerUser(userData) {
  const user = await userService.create(userData);
  const authProfile = await authService.create(user.id);
  const wallet = await paymentService.createWallet(user.id);

  // If step 3 fails, we have orphaned records
  // Welcome to distributed systems!
}
Enter fullscreen mode Exit fullscreen mode

Debugging Became Archaeological Work

One API call now touched 4 services, 4 databases, and generated logs across 12 different containers.

"Why is checkout slow?" became a 2-hour investigation involving:

  • Service mesh tracing
  • Log aggregation queries
  • Database performance monitoring
  • Network latency analysis

The Breaking Point

Black Friday traffic hit. Our beautiful microservices architecture gave us:

  • Cascading failures when one service went down
  • Database connection exhaustion across 4 separate pools
  • Network timeouts because services couldn't find each other
  • Debugging hell with distributed tracing gaps

The monolith would've just... scaled horizontally. Like it had been doing for years.

What I'd Do Differently Today

Start With a Modular Monolith 

// Clean boundaries, single deployment
const userModule = require('./modules/user');
const orderModule = require('./modules/order');
const paymentModule = require('./modules/payment');

// Easy to extract later if needed
Enter fullscreen mode Exit fullscreen mode

Extract Services Only When You Have To

  • Team size: Can't coordinate? Extract.
  • Technology needs: Different languages required? Extract.
  • Scale differently: 1000x more reads than writes? Extract.
  • Compliance: Different security requirements? Extract.

Embrace the Distributed Monolith Phase

Instead of fighting it, plan for it:

  • Shared databases initially
  • Async communication from day one
  • Circuit breakers everywhere
  • Comprehensive observability

The Lessons

  1. Microservices are a team structure solution, not a technical one
  2. Network calls are not function calls - they fail differently
  3. Data consistency is hard - really, really hard
  4. Operational complexity grows exponentially
  5. Sometimes boring is better than cutting-edge

Current Approach

We went back to a modular monolith with:

  • Clear module boundaries
  • Async event patterns
  • Horizontal scaling
  • Feature flags for gradual rollouts

It's not as exciting as microservices, but it ships features and sleeps well at night.

🔗 Related Reads

What's your microservices horror story? Or are you still in the "this will solve everything" phase? No judgment - we've all been there! Share your distributed systems scars below 🤕

Tomorrow: Friday Stack Pack - Weekend tools that won't make you question your life choices

Top comments (0)