Mercado Pago in Next.js: the complete flow with webhooks
Creating the preference, verifying the webhook signature, and the race condition nobody documents: what happens when the webhook beats the redirect.
Blog
Notes on web development, architecture, and the technical decisions behind the products we build.
Why I used a BFF pattern to separate Next.js from my backend
How a Backend-for-Frontend keeps tokens out of the browser and lets the frontend evolve without touching the API. With a real example from an e-commerce platform.
How to revoke a JWT instantly without storing sessions
The classic JWT problem is that you can't revoke a token until it expires. Token versioning solves it with one integer — no Redis, no session table.
From EmailJS to server-side sending: why keys don't belong in the browser
EmailJS is convenient until you see your credentials sitting in the bundle. The migration to an API route, double opt-in, and what it does for deliverability.
Rate limiting without Redis: how far in-memory state actually gets you
Most rate limiting guides assume Redis from minute one. In-memory state is imperfect, but often enough for a contact form. Where the line actually is.
Multi-tenancy: choosing between one database, one schema, or one column
Three ways to isolate tenants in a SaaS, with the real trade-offs. Why I chose a discriminator column for a property platform, and when I wouldn't.
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