Don't let the LLM do the math 🔗
Keep pricing and numbers deterministic in AI products. Let the LLM write prose only. A hybrid architecture from a real deployment advisor. [...]
Flavio Copes
Posts
First-party analytics with SQLite 🔗
Build product analytics with a SQLite events table in D1 instead of Google Analytics: whitelisted events, server tracking, beacons, funnel SQL. [...]
Playwright tutorial: end-to-end testing from scratch 🔗
Learn Playwright end-to-end testing from scratch: install it, write resilient tests, handle login, mock APIs, debug failures, and run everything in CI [...]
Dynamic sitemap.xml in Astro SSR 🔗
Generate sitemap.xml and robots.txt dynamically in Astro SSR without @astrojs/sitemap. API routes, typed registries, and testable pure functions. [...]
How I added Polar payments to an Astro app 🔗
Add Polar payments to Astro with subscriptions, one-time purchases, Better Auth, webhooks, D1 entitlements, and local testing. [...]
Better Auth in Astro on Cloudflare Workers 🔗
Better Auth setup for Astro SSR on Cloudflare Workers: D1 Drizzle adapter, catch-all auth route, session in middleware, no Node dependencies. [...]
Versioning reference data with effective_from dates 🔗
Version reference data in SQLite with effective_from dates instead of overwriting rows. Keep pricing history and drive changelog notifications. [...]
I launched fstack 🔗
fstack is my free collection of 13 simple agent skills for Cursor, Claude Code, Codex, and any agent that supports skills. [...]
The AI Guide for Developers 🔗
A developer's guide to AI: how I use AI agents and coding tools in my daily work, with links to my posts on agent frameworks and workflows. [...]
The Alpine.js Guide 🔗
Alpine.js guide: what Alpine is, why it's great for adding interactivity to server-rendered sites, and how it fits the AHA Stack. [...]
The Astro Guide 🔗
Learn Astro with this guide: components, props, layouts, data fetching, SSR patterns and real-world tips from running my own sites on Astro. [...]
The C Guide 🔗
Learn C programming from scratch: variables, pointers, arrays, strings, structures, and the preprocessor. A guided path through the C tutorials on thi [...]
The Command Line Guide 🔗
Learn the command line: shells, essential Unix commands, file management, processes and Bash scripting, with a clear path through my tutorials. [...]
The Cloudflare Guide 🔗
Learn the Cloudflare developer platform: Workers, KV, D1, R2, Queues, Durable Objects and more, through my hands-on tutorial series. [...]
The Go Guide 🔗
Learn Go programming: a guided path through Go basics, slices, maps, structs, interfaces, plus hands-on projects like CLI tools and a REST API. [...]
The HTML Guide 🔗
HTML is the foundation of every web page. Learn tags, forms, images, media and accessibility with this curated guide to the best HTML tutorials. [...]
The htmx Guide 🔗
htmx guide: what htmx is, why hypermedia-driven apps beat SPA complexity for most projects, and how htmx fits the AHA Stack. [...]
The Laravel Guide 🔗
Learn Laravel: a guided path through routing, Blade templates, migrations, Eloquent, authentication, forms, and deployment with Laravel Forge. [...]
The PHP Guide 🔗
Learn PHP from scratch: setup, first programs, handling HTTP requests, forms, cookies, sessions, errors, Composer, and deploying PHP applications. [...]
The Python Guide 🔗
Learn Python from scratch: a guided path through variables, data types, functions, classes, modules, files, and the tooling around the language. [...]
The SQL and Databases Guide 🔗
Learn SQL and databases: database theory, SQL fundamentals like SELECT and joins, plus practical guides to PostgreSQL, SQLite and MySQL. [...]
The Swift Guide 🔗
Learn Swift and iOS development: a guided path through Swift fundamentals, optionals, structs, protocols, and building interfaces with SwiftUI. [...]
Transactional email from Workers with Resend 🔗
Send transactional email from Cloudflare Workers with Resend over fetch, no Node SDK. Graceful no-op without an API key, plus KV deduped alerts. [...]
How I use the same Git work log with Codex and ChatGPT 🔗
Codex and ChatGPT can install the same native post-commit logger I use with Cursor, keeping every project's work in one text file. [...]
How I log every Git commit to a plain text file 🔗
I use Git's native post-commit hook to keep one reverse-chronological work log, with Cursor installing it automatically in each project. [...]
fstack, the simple stack 🔗
I built my own agent skill collection: 13 skills, plain names, one job each. Here's why it exists and how it works. [...]
Astro SSR with D1 and Drizzle ORM 🔗
Wire Cloudflare D1 into an Astro SSR app with Drizzle ORM. Bindings, schema, migrations, and local dev with Miniflare in one setup guide. [...]
Rate limiting with Cloudflare KV 🔗
Rate limit Cloudflare Workers API routes with KV fixed-window counters and expirationTtl cleanup. Soft limits that work with KV eventual consistency. [...]
The Summer of Code, update #2 🔗
Four days after my first Summer of Code update: 73 more tools, 12 quiz courses, fstack, a rebuilt Cook with AI, and a Git work log. [...]
What iPhone Developer Mode does, and when you should enable it 🔗
Learn what iPhone Developer Mode unlocks for Xcode, debugging, Instruments, and local apps, plus its security and privacy tradeoffs. [...]