Building Scalable Microservices with Node.js and Kubernetes

# Building Scalable Microservices with Node.js and Kubernetes When we hit 1 million users, our monolithic architecture started showing cracks. Here's how we rebuilt our platform using microservices. ## The Problem with Monoliths Our Django monolith served us well initially, but we faced: - 30-minute deployment times - Single point of failure - Inability to scale individual components - Technology lock-in ## Microservices to the Rescue We broke down our application into focused services: ### User Service ```javascript // user-service/index.js const express = require('express'); const app = express(); app.get('/users/:id', async (req, res) => { const user = await getUserById(req.params.id); res.json(user); }); app.listen(3001, () => { console.log('User service running on port 3001'); }); ``` ### Order Service ```javascript // order-service/index.js const express = require('express'); const app = express(); app.post('/orders', async (req, res) => { const order = await createOrder(req.body); await publishEvent('order.created', order); res.json(order); }); ``` ## Kubernetes Configuration Here's our deployment configuration: ```yaml apiVersion: apps/v1 kind: Deployment metadata: name: user-service spec: replicas: 3 selector: matchLabels: app: user-service template: metadata: labels: app: user-service spec: containers: - name: user-service image: myapp/user-service:latest ports: - containerPort: 3001 env: - name: DATABASE_URL valueFrom: secretKeyRef: name: db-secret key: url ``` ## Service Mesh with Istio We use Istio for: - Traffic management - Security - Observability - Policy enforcement ## Monitoring and Observability Our stack includes: - **Prometheus**: Metrics collection - **Grafana**: Visualization - **Jaeger**: Distributed tracing - **ELK Stack**: Centralized logging ## Lessons Learned 1. **Start with a monolith**: Microservices add complexity 2. **Automate everything**: CI/CD is non-negotiable 3. **Invest in observability**: You can't fix what you can't see 4. **Design for failure**: Services will go down 5. **Keep services small**: If it takes more than 2 weeks to rewrite, it's too big ## Performance Results After migration: - **Deployment time**: 30 minutes → 5 minutes - **Availability**: 99.9% → 99.99% - **Response time**: 200ms → 50ms - **Infrastructure cost**: Reduced by 40% ## What's Next? We're exploring: - Service mesh migration to Linkerd - GraphQL federation - Edge computing with Cloudflare Workers - Serverless functions for event processing ## Conclusion Microservices aren't a silver bullet, but for our use case, they provided the scalability and flexibility we needed. Start simple, measure everything, and evolve your architecture based on actual needs, not hype. Have questions about our architecture? Drop them in the comments!