Preview Environments & Deployment

From ephemeral sandbox to production URL

Preview environments are where generated code meets reality. Master tenant isolation at scale, hot module replacement, dependency management, the preview-to-production pipeline, custom domains, and rollback as a safety primitive.

Modules in This Level

3.1 Anatomy of a Preview Environment

Map the four components of a preview environment — runtime, filesystem, network layer, and process manager — and trace the lifecycle from creation through code injection, dependency install, dev server start, and teardown, understanding why each stage has a hard latency target.

3.2 Tenant Isolation at Scale

Learn to defend multi-tenancy investment with concrete mechanisms — hard CPU limits, memory OOM kill, I/O throttling, and bin packing headroom — and explain why shared-process, container-per-tenant, and VM-per-tenant carry fundamentally different risk profiles at Make's scale.

3.3 Hot Reloading and Incremental Updates

Understand the HMR protocol — filesystem watching, module dependency graph diffing, WebSocket delivery, and React Fast Refresh state preservation — and learn why Vite's native-ESM approach makes incremental preview updates sub-100ms while Webpack rebuilds can take 10+ seconds.

3.4 Dependency Management in Ephemeral Environments

Learn why npm install is slow and evaluate the three caching strategies — global tarball cache, pre-built node_modules snapshots, and layered incremental caching — that can reduce a 20-second install to under 1 second for common stacks without losing correctness guarantees.

3.5 From Preview to Production Deployment

Understand what the production build step changes — minification, tree-shaking, code splitting — and evaluate three hosting models (static CDN, serverless, container server) to determine what kinds of apps Make users can ship and how Make's story compares to Vercel and Netlify.

3.6 Custom Domains, SSL, and the Edge

Learn the custom domain flow — CNAME setup, DNS propagation, Let's Encrypt provisioning, automated renewal, and health monitoring — and why this is the retention milestone where Make apps become indistinguishable from hand-built deployments.

3.7 Rollback, Versioning, and Deployment Safety

Learn how immutable artifacts and pointer-based routing make sub-30-second global rollback possible, how blue-green deployments reduce shipping risk, and what deployment versioning metadata Make needs to give users a meaningful, recoverable history of what they shipped.

3.8 Level 3 Checkpoint

Apply Level 3 deployment knowledge to a real architecture decision: evaluate a proposal to deploy all Make apps as static sites to a CDN, and navigate the pushback from teams who need server-side rendering, API routes, and database access at request time.