Executive Summary

Design patterns for PWAs that keep working when connectivity fails—then sync cleanly when it returns.

Offline-first isn’t nostalgia. It’s reliability. If your product breaks without Wi‑Fi, your users will treat it like a toy.

The trick is separating ‘capture’ from ‘compute’: collect inputs locally, queue actions, then sync and process when connectivity returns.

“Production is where good ideas meet boring reality. The winners instrument the boring part.”
AI & Dev Dispatch

The Core Idea

Most “AI failures” are system failures: missing contracts, missing logs, missing ownership lines. Fix the system, and the model suddenly looks smarter.

Contract

Define the stable input/output boundary first.

Logs

Capture raw facts, not just summaries.

Policy

Centralize allow/deny decisions and expose reason codes.

UX

Make failure legible and recoverable.

// Outbox pattern (client-side).
outbox.put({
  id: uuid(),
  type: "CREATE_NOTE",
  payload,
  created_at: Date.now(),
  status: "PENDING",
  retries: 0
});

That snippet is not a complete app. It’s a reminder: your system should prefer verifiable facts over narrative.

Failure Modes You’ll Actually See

  • Sync conflicts

    Two devices edit the same entity. Decide: last-write-wins, merge, or reject.

  • Over-syncing

    Sync everything is expensive and fragile. Sync what matters, when it matters.

  • Opaque queues

    Users need to see what’s pending, failed, or sent.

  • No fallback modes

    AI calls should be optional; core workflows must still function.

Implementation Notes

Use an outbox table in IndexedDB: pending actions, payload hash, retries, last_error.

Design conflict resolution up front—don’t pretend it won’t happen.

Defer AI calls: queue ‘enrichment’ jobs and show UI state instead of blocking workflows.

For architecture and rollout planning, use the Contact Hub.

Ship‑Ready Checklist

Use this as a pre‑deploy gate. If you can’t check these boxes, don’t pretend you’re “done.”

- A single source of truth for versions (prompt/policy/schema) and a way to display them in-app.
- Request correlation ID visible in UI, logged server-side, and searchable.
- Explicit failure UX: what happened, why, and a safe next step.
- An audit trail you can replay: inputs, decisions, outputs, and cost facts.
- A small test harness (even 20 cases) that runs before deployment.

Want this turned into a working product?

Use the Contact Hub to scope features, security, billing, and the deployment plan.

Open Contact Hub