I wanted to figure out how people build payment systems without losing everyone's money. It turns out, my first attempt was a great way to lose a lot of it. I started with what felt like a simple Go service. One endpoint, one database table, and a third-party provider to handle the actual charging. The plan was straightforward: Decode the request. Call the provider to charge the user. Save the res
An opinionated list of Python frameworks, libraries, tools, and resources
What if your Kubernetes cluster simply refused to run unsigned images? I spent some time experimenting with enforcing image provenance in a small Kubernetes setup using MicroK8s. The idea was simple: Only container images with valid cryptographic signatures are allowed to run in the cluster. For this I used: GitLab CI/CD (build + signing pipeline) Cosign / Sigstore (image signing) Kyverno (admissi
We are currently witnessing a massive shift in AI development. We’ve moved past the "Chatbot" era and into the era of Agentic Systems—AI that doesn’t just suggest text, but actually executes code, moves money, and modifies databases. However, there is a fundamental architectural flaw in how most agents are built today: we are giving "Intelligence" and "Authority" to the same probabilistic model.
Most teams I have worked with have one auth test in their suite. It looks like this: test('valid token verifies', () => { const token = signSync({ sub: 'user-1', aud: 'api://backend' }, secret); const result = verify(token, options); expect(result.valid).toBe(true); }); That test is fine. It is also a smoke test, not a regression suite. It catches the case where verification is completely b
The on-call alert at 02:14 said auth_5xx_rate spiked from 0.01 to 31.4. Not a deploy window. Not a traffic spike. Just thirty-one percent of authenticated requests failing for ~four minutes, then back to baseline. The cause was a JWKS rotation on the issuer side. New keys came in. Old keys went out. Caches in our service didn't refresh fast enough. Tokens signed with the new key were rejected beca
I was reading a Stripe tutorial last week and watched the author write amount: req.body.amount. That single line lets any user buy Premium for $1. It's also a common pattern in Stripe Checkout starter code. This post is about why, and how to make it impossible. You're building a paywalled product. You wire up Stripe Checkout, follow a popular tutorial, ship it. Looks great. Tests pass. Users are p