Testing
PCI DSS compliance testing is about verifying that cardholder data is handled securely — not stored when it shouldn't be, encrypted when transmitted, and accessible only to authorized systems. Most developers don't need to handle raw card data at all if they use Stripe or Braintree'
Testing
Payment API calls in unit tests create slow, flaky tests with real rate limits and network dependencies. The solution is mocking at the HTTP layer — stripe-mock (a local Stripe API server), nock (Node.js HTTP interceptor), or VCR cassettes (recorded responses replayed in tests). Each approach has trade-offs. This guide
AI Testing
Prompts are code — they should be versioned, tested, and reviewed like any other critical system component. This guide covers the practices that teams use to test prompts systematically before shipping changes and catch regressions as models evolve. Key Takeaways Treat prompts as first-class artifacts. Store them in version control, review
Testing
PayPal and Braintree both provide sandbox environments that mirror their production APIs. PayPal Sandbox uses test buyer/seller accounts. Braintree Sandbox provides test nonce values for different payment scenarios. Both support webhook testing for order completion and payment events. This guide covers setup, test credentials, automation patterns, and common gotchas.
Testing
Stripe subscription testing requires simulating billing cycles, plan changes, and edge cases that only appear over time. Stripe's test mode lets you fast-forward time, trigger immediate renewals, and test proration calculations without waiting for real billing cycles. This guide covers how to test subscription creation, upgrades, cancellations, trial
AI Testing
LLM hallucinations — confidently stated falsehoods — are one of the hardest failure modes to catch because they look identical to correct outputs. This guide covers the practical techniques developers use to detect hallucinations in production systems and reduce their frequency. Key Takeaways Hallucinations are silent failures. A crashed request is easy
Testing
Stripe's test mode lets you run complete payment flows without real money. Test card numbers like 4242 4242 4242 4242 simulate successful payments, while other numbers simulate declines, insufficient funds, and 3D Secure authentication. This guide covers how to test the full checkout flow using Playwright, handle authentication
Testing
Stripe webhooks are HTTP POST requests Stripe sends to your server when payment events occur. Testing them requires replaying signed events against your handler without depending on real Stripe infrastructure. This guide covers stripe-cli for local forwarding, constructing test payloads in pytest, verifying webhook signatures, and running webhook tests in
AI Testing
Testing LLM outputs is different from testing deterministic software. Outputs vary across runs, so you need a combination of rule-based checks, semantic similarity, and LLM-as-judge techniques. This guide walks through practical methods developers use to validate AI-generated text in production. Key Takeaways LLM outputs are probabilistic — plan your tests accordingly.
SRE
SLI, SLO, and error budget are the vocabulary of reliability engineering. They give you a rigorous way to answer "is our service reliable enough?" and "how much risk can we take with this deployment?" without relying on gut feeling or incident retrospectives. This guide covers how
SRE
Synthetic monitoring runs scripted tests against your application continuously — from multiple geographic locations, using real browsers or API clients — to detect issues before users report them. Combined with canary deployments, it becomes your automated deployment safety net. Synthetic Monitoring Fundamentals Synthetic monitors are different from real user monitoring (RUM): Synthetic
SRE
When an incident happens at 3 AM, the quality of your response depends on two things: the quality of your runbooks and how many times your team has practiced them. Testing runbook automation and running incident drills converts theory into muscle memory. Automated Runbooks vs. Reference Runbooks Reference runbooks are