Docker Tips That Actually Matter in 2026

After running Docker in production for years, here are the tips that actually make a difference. 1. Multi-Stage Builds Are Non-Negotiable Stop shipping build tools in your production images: # Build stage FROM node:20-alpine AS builder WORKDIR /app COPY package*.json ./ RUN npm ci COPY . . RUN npm run build # Production stage FROM node:20-alpine WORKDIR /app COPY --from=builder /app/dist ./dist COPY --from=builder /app/node_modules ./node_modules EXPOSE 3000 CMD ["node", "dist/index.js"] This typically reduces image size by 60-80%. 2. Layer Caching Strategy Docker caches layers from top to bottom. Order your Dockerfile instructions from least to most frequently changing: # Changes rarely FROM node:20-alpine WORKDIR /app # Changes occasionally COPY package*.json ./ RUN npm ci # Changes frequently COPY . . RUN npm run build This way, npm ci only runs when dependencies change, not every code change. 3. Use .dockerignore Your .dockerignore should be as thorough as your .gitignore : node_mo