# WebClient Proxy Configuration Leading to Connection Timeout ## Summary A timeout error occurred when using Spring WebClient configured with an HTTP proxy. Despite correctly setting the proxy host and port, requests consistently failed with connection timeouts. The issue arose in a Java application leveraging Project Reactor’s HttpClient. ## Root Cause – **Proxy configuration wasn’t … Read more
# Postmortem: Batch Video Cropping Failure via FFmpeg Script ## Summary An automation attempt to crop multiple videos using FFmpeg in a Windows batch script failed due to unresolved placeholders in filter parameters and improper variable handling. The script executed without error detection but produced incorrect outputs. ## Root Cause – **Undefined crop parameters**: Placeholders … Read more
Best practices to harden a Python experiment hook that triggers an external quota increase Summary A minimal Python experiment hook randomly assigned users to control/treatment groups and called an external quota service. Production incidents occurred where duplicate quota increases, inconsistent assignment state, and traffic spikes caused: Permanent quota over-allocation to treated users Experiment group contamination … Read more
# Technical Postmortem: MissingMethodException in Blazor Web App During OIDC Token Validation ## Summary A Blazor Web App targeting .NET 9.0 failed during authentication with a `System.MissingMethodException` when calling `OpenIdConnectHandler.ValidateTokenUsingHandlerAsync()`. The application crashed at startup due to an incompatible version of `Microsoft.IdentityModel.Tokens`, specifically related to the `TokenValidationResult` constructor signature. Key details: – Exception: `Method not … Read more
# Postmortem: Handling Negative Assertions in Robot Framework for MQTT Event Verification ## Summary A critical gap was identified in automated tests for an IoT lighting system: Robot Framework had no explicit mechanism to confirm the **absence** of an expected MQTT message within a defined time window during night-mode operations. This led to incomplete verification … Read more