Multi-tenancy means one running application serves many customers while keeping their data apart. Here is what it means, the apartment-building analogy that makes it click, the three models, and how tenants stay separated, with links to go deep on each.
Assistants like Copilot, Cursor, and Claude Code ship features fast and ship security holes at the same speed. Here are the flaws they reliably produce, with real before-and-after code, and how to use AI to catch them before an attacker does.
AI assistants can now scan your codebase for vulnerabilities and propose patches. Here is how to wire that into a real pipeline, why you still keep a deterministic scanner next to it, and the four places it will lie to you if you let it.
Row-Level Security is one layer, not the whole answer. Real tenant isolation is defense in depth across the data, the API, and the keys, so that no single mistake exposes another customer. Here are the layers and where each one earns its place.
Row-Level Security moves tenant isolation out of every developer's memory and into the database itself. Here is the exact Postgres pattern for a pooled multi-tenant app, plus the four footguns that leak data in production if you miss them.
Most AWS bills carry 20 to 40 percent waste, and cutting it does not take a FinOps team. This is the whole method in four steps: see where the money goes, kill the waste, pay less for what remains, and keep the bill down for good. Each step links to its own deep dive.
