A markdown preview doesn’t need a client markdown parser. I render the preview server-side (same pipeline used in production), and load it into a Turbo Frame. The editor form includes a frame called preview, and a “Preview” button submits the form to

Creating a new TCP/TLS connection for every request is slow and it adds load on both sides. For high-traffic services calling a small set of upstreams, keep-alive reduces latency and CPU dramatically. I configure an https.Agent with sensible maxSocket

For long text entry, autosave is a huge quality-of-life improvement. I implement it with a Stimulus controller that debounces input and submits the form to a drafts endpoint in the background. The response is a turbo stream that updates a “Saved at …”

Nested fields are a common Rails pain point, and the old solution was heavy JS gems. With Stimulus, I keep it minimal: render a hidden <template> containing the fields with a placeholder index, then on “Add” clone it and swap the placeholder for

A modal is just a frame boundary. Load the modal content into a dedicated frame, then on submit broadcast/stream a close action plus a list update. You get “SPA modal UX” without a frontend router.

Deadlocks happen under load. When the operation is safe to retry, rescue the deadlock exception and retry with jitter. Keep retries bounded and log when it happens.

Route tests give me fast feedback about the API contract without needing a full browser. I structure the app so I can import an app instance without binding a port, then use supertest to make requests. The key detail is determinism: stub time and rand

Shipping a deploy with a missing env var is an easy way to create a confusing outage. process.env is just a bag of strings, so I parse env at startup, validate required variables, and fail fast with a clear message. The other win is type safety: once

Database transactions ensure data integrity when multiple operations must succeed or fail together. I use @transaction.atomic on views or functions to wrap them in a transaction. For partial rollbacks, I use transaction.atomic() as a context manager a

I create custom permission classes to encapsulate authorization logic outside of views. This IsOwnerOrReadOnly pattern is useful for resources where anyone can read but only the owner can modify. By implementing has_object_permission, I can make granu

Sometimes you need a one-time maintenance operation outside normal schema changes. Use a small table to track “run once” tasks so reruns are safe and the operation is visible.

Emails should be idempotent. Store a delivered marker (or unique key) so retries don’t spam users. This pattern is especially useful for receipts and password reset flows.