Every service needs to send messages to users, whether through AlimTalk, email, or push notifications. But implementing notification delivery as a simple HTTP call quickly runs into limits. Each problem can be solved with another tool: consolidate delivery into one module, enforce a rate limit inside the function, create timing branches with a scheduler, and record delivery…
Kubernetes provides two kinds of probes for determining a Pod's state. A liveness probe asks, "Is this container alive?" The kubelet periodically calls a configured endpoint and restarts the container if the call fails or receives no response. This automatically recovers an application that has become unresponsive because of a deadlock or memory leak.
I believed that strong technical skills were all that mattered: clean code, refactoring, TDD, and domain-driven design. I kept practicing because I thought writing good code was a developer's highest virtue. Then the AI era shook that assumption. I realized that writing code well is no longer enough to create irreplaceable value. So what should developers truly focus on?
Have you ever introduced a CDN only to find the monthly cost burdensome? Our team cut more than one million won in annual CDN costs through browser-cache configuration alone. All it took was setting the Cache-Control header correctly. This article explains the fundamentals of CDNs and Cache-Control, then shares how we used browser caching to reduce costs in practice.
An event is being held to celebrate a celebrity's visit, with tickets available only to the first 1,000 people. Applications will be accepted through a web application. Suppose you protect the system with a distributed lock. Are you confident that concurrency is now completely under control?