AI coding guides & resources
Engineering decisions, tutorials, and video guides from the OTF team.
Supabase realtime keeps mobile presence honest without polling your database dead
Stop polling your database from mobile clients. Supabase Realtime patterns for presence, live rows, and reconnects that survive the OS.
7 min read
Defend your AI features against prompt injection: production patterns that hold
Untrusted input reaches your model from everywhere: delimit it, constrain the tools, validate the output, and keep a human on the dangerous path.
5 min read
One crashing screen should not kill the app: error boundaries that hold
A bad render in one corner should not blank the whole app. Here is where to place boundaries, log, and recover.
9 min read
Supabase Row Level Security keeps AI-built mobile data safe from day one
Your anon key ships in the app bundle. Row Level Security is what stops strangers reading other users' rows.
9 min read
Deep links that open the right screen: production checklist for Expo apps
Cold starts, expired sessions, and pasted links break deep links. The Expo setup that routes every link right.
9 min read
Ship privacy labels you can defend: data honesty for AI-built apps
Your store listing answers for your data practices: audit every SDK, declare every collection, and fill both privacy forms without guessing.
6 min read
Price your AI-built app honestly: the ownership math that keeps you shipping
Add up what an AI-built app really costs to run: stores, payments, backend, and the rebuild bill — then keep every line item under your control.
6 min read
RevenueCat paywalls in Expo apps work when entitlements own the gating logic
Add subscriptions to your Expo app without hand-rolling StoreKit: dev builds, entitlements, and review-safe paywalls.
8 min read
Expo SQLite offline cache keeps AI-built apps usable when signal drops
Signal drops in lifts and metros. A local SQLite cache keeps reads instant and queues writes for sync.
8 min read
Expo Router auth guards that survive expired sessions and deep links
Stop logged-out flashes and dead deep links: Expo Router guard layout with refresh-safe session checks, protected groups, and cold-start redirects.
8 min read
Preview deployments keep AI coding agents honest before merge
Every AI agent PR gets a live preview URL. Here is the five-minute check that catches broken agent output before merge.
8 min read
Supabase Edge Functions carry the mobile backend logic your client should never hold
Move secrets, webhooks, and quota checks into Supabase Edge Functions for a thinner Expo client.
8 min read
FlashList v2 earns its place in every production React Native feed
FlashList v2 is new-architecture-only with view recycling and no size estimates. This migration checklist keeps your production feeds smooth.
7 min read
The eject button myth: exporting your AI-built app does not save it
The eject button is real but it will not save you: what exported AI-built code actually contains, and the drill that proves it.
6 min read
Choose a starter kit once: the six checks that prevent a full rewrite later
A six-gate selection procedure that keeps your starter kit from becoming a full rewrite three months later.
7 min read
Stay signed in: Supabase Auth session persistence in Expo apps
End random logouts after restart: SecureStore session storage, background refresh, OAuth redirect wiring, and sign-out that actually clears.
8 min read
Supabase auth hardening checklist that keeps production sign-in safe
Harden production auth: redirects, row-level policies, server-only keys, session tests, and an attacker-style checklist.
8 min read
Offline-first mutation queue keeps Expo apps working when the network drops
An outbox-pattern mutation queue with retries and restart-safe persistence keeps your Expo app correct on flaky networks. Here is the production setup.
7 min read
Sentry error tracking for React Native in production: the release checklist
A production checklist for Sentry error tracking in React Native: source maps, safe context, release health, privacy, testing, and actionable triage.
9 min read
EAS build secrets stay out of bundles when env profiles and eas.json split right
Service keys baked into Expo bundles are public the moment you ship. This profile split keeps them out.
7 min read
Supabase Storage uploads that survive real mobile networks in Expo apps
Ship reliable Expo uploads with Supabase Storage: signed URLs, RLS policies, retries, compression, and cleanup.
8 min read
EAS Update rollback plan keeps one bad bundle from stranding your users
A bad OTA bundle reaches every device at once. Pin runtimes, gate updates, and keep a rollback you can run half-asleep.
7 min read
Claude Fable 5.1 verdict: when Anthropic's $10-per-million reasoning model earns its keep
Claude Fable 5.1 costs 5x Sonnet 5 per output token — the verdict on when Anthropic's reasoning flagship earns its keep.
6 min read
GPT-6 Astra raises the bar on computer use: what builders should change before shipping
OpenAI's GPT-6 Astra moves the computer-use frontier — here's how production builders should adapt evals, guardrails, and ship checklists.
7 min read
