Reliability
101 bites tagged Reliability — interview questions with model answers, and 60-second explainers.
High Availability: Designing Systems That Don't Go Down
High Availability (HA) means designing systems to survive failures by having redundant components ready to take over instantly. It's essential for services like payment gateways where downtime costs money and user trust.
Service Level Objective (SLO): A Measurable Promise
An SLO is a precise, measurable promise about your service's performance, like "99.9% of requests will succeed." It's the internal engineering target that backs up a customer-facing SLA. The footgun is setting a 100% SLO, which leaves no room for failure.
Kubernetes Health Checks: Liveness, Readiness, and Startup Probes
Kubernetes health checks ask your app: "Are you alive?" (liveness), "Ready for traffic?" (readiness), and "Done starting?" (startup). This lets it automate restarts and traffic routing for zero-downtime deployments.
Idempotency: Safe to Retry Automation
Idempotent automation ensures an operation has the same effect whether run once or many times. This is vital for safely retrying failed CI/CD jobs or configuration scripts. The footgun: thinking it means 'no side effects'.
Root Cause Analysis: Stop Fixing Symptoms, Find the Source
Root Cause Analysis digs past surface-level symptoms to find the true origin of a problem. It’s used to analyze IT outages, manufacturing defects, and even medical misdiagnoses.
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