https://www.formoseaniap.com/engineer/articles.html?lang=en Technical engineering articles. en-us https://www.formoseaniap.com/engineer/article.html?id=solo-platform-engineering-vibe-coding-diary-part-8&lang=en https://www.formoseaniap.com/engineer/article.html?id=solo-platform-engineering-vibe-coding-diary-part-8&lang=en Sun, 26 Apr 2026 00:00:00 GMT The gap between 'it works' and 'it feels right,' and why human feedback was irreplaceable even in an AI-assisted workflow. https://www.formoseaniap.com/engineer/article.html?id=solo-platform-engineering-vibe-coding-diary-part-7&lang=en https://www.formoseaniap.com/engineer/article.html?id=solo-platform-engineering-vibe-coding-diary-part-7&lang=en Sun, 26 Apr 2026 00:00:00 GMT Five stages of CSS debugging — from ragged text edges to a CSS Grid min-content trap — each narrowing the problem even when earlier fixes turned out to be wrong. https://www.formoseaniap.com/engineer/article.html?id=solo-platform-engineering-vibe-coding-diary-part-6&lang=en https://www.formoseaniap.com/engineer/article.html?id=solo-platform-engineering-vibe-coding-diary-part-6&lang=en Sun, 26 Apr 2026 00:00:00 GMT A production incident where two CloudFront cache behaviors produced the same cache key, causing the main site and engineering section to serve each other's content. https://www.formoseaniap.com/engineer/article.html?id=solo-platform-engineering-vibe-coding-diary-part-5&lang=en https://www.formoseaniap.com/engineer/article.html?id=solo-platform-engineering-vibe-coding-diary-part-5&lang=en Sun, 26 Apr 2026 00:00:00 GMT A reviewer said personal content confused hiring managers. The subdomain approach hit the CloudFront Free plan limit. The pivot to path-based routing changed the architecture. https://www.formoseaniap.com/engineer/article.html?id=solo-platform-engineering-vibe-coding-diary-part-4&lang=en https://www.formoseaniap.com/engineer/article.html?id=solo-platform-engineering-vibe-coding-diary-part-4&lang=en Sun, 26 Apr 2026 00:00:00 GMT Stale HTML behind two CDN layers, a podcast CORS puzzle, GitHub Actions OIDC debugging, and a deploy that broke every stylesheet on the site. https://www.formoseaniap.com/engineer/article.html?id=solo-platform-engineering-vibe-coding-diary-part-3&lang=en https://www.formoseaniap.com/engineer/article.html?id=solo-platform-engineering-vibe-coding-diary-part-3&lang=en Sun, 26 Apr 2026 00:00:00 GMT Going live with Cloudflare and Route 53, the 60-day nameserver lock that blocked the DNS migration, and the workarounds that kept the site running. https://www.formoseaniap.com/engineer/article.html?id=solo-platform-engineering-vibe-coding-diary-part-2&lang=en https://www.formoseaniap.com/engineer/article.html?id=solo-platform-engineering-vibe-coding-diary-part-2&lang=en Sun, 26 Apr 2026 00:00:00 GMT Migrating from Medium to a self-hosted Markdown pipeline, and the taxonomy pivot that followed when the initial article organization did not scale. https://www.formoseaniap.com/engineer/article.html?id=solo-platform-engineering-vibe-coding-diary-part-1&lang=en https://www.formoseaniap.com/engineer/article.html?id=solo-platform-engineering-vibe-coding-diary-part-1&lang=en Sun, 26 Apr 2026 00:00:00 GMT How I built a full AWS-hosted portfolio platform solo by pairing with VS Code (Codex) — the methodology, the failures, and the tactics that actually worked. https://www.formoseaniap.com/engineer/article.html?id=technical-devops-sre-diaries-building-a-reliable-maintenance-mode-part-5-future-directions-and-sre-reflections&lang=en https://www.formoseaniap.com/engineer/article.html?id=technical-devops-sre-diaries-building-a-reliable-maintenance-mode-part-5-future-directions-and-sre-reflections&lang=en Tue, 24 Mar 2026 00:00:00 GMT Future directions for the maintenance-mode tool, from Lambda and Slack automation to broader reflections on continuous improvement in SRE. https://www.formoseaniap.com/engineer/article.html?id=technical-devops-sre-diaries-p0-incidents-site-unaccessible-but-accessible-part-4-tools-and-reflections&lang=en https://www.formoseaniap.com/engineer/article.html?id=technical-devops-sre-diaries-p0-incidents-site-unaccessible-but-accessible-part-4-tools-and-reflections&lang=en Tue, 24 Mar 2026 00:00:00 GMT A practical recap of the DNS commands, lookup tools, and SRE lessons that helped resolve this misleading outage. https://www.formoseaniap.com/engineer/article.html?id=technical-devops-sre-diaries-building-a-reliable-maintenance-mode-part-4-challenges-behind-the-tool&lang=en https://www.formoseaniap.com/engineer/article.html?id=technical-devops-sre-diaries-building-a-reliable-maintenance-mode-part-4-challenges-behind-the-tool&lang=en Tue, 24 Mar 2026 00:00:00 GMT The engineering detours behind the new tool, from legacy DNS confusion to WAF state tokens and CLB-to-ALB migration surprises. https://www.formoseaniap.com/engineer/article.html?id=technical-devops-sre-diaries-p0-incidents-site-unaccessible-but-accessible-part-3-response-and-communication&lang=en https://www.formoseaniap.com/engineer/article.html?id=technical-devops-sre-diaries-p0-incidents-site-unaccessible-but-accessible-part-3-response-and-communication&lang=en Tue, 24 Mar 2026 00:00:00 GMT How the team handled the NS rollback, customer communication, and propagation risk after a confusing DNS outage. https://www.formoseaniap.com/engineer/article.html?id=technical-devops-sre-diaries-building-a-reliable-maintenance-mode-part-3-the-new-tool&lang=en https://www.formoseaniap.com/engineer/article.html?id=technical-devops-sre-diaries-building-a-reliable-maintenance-mode-part-3-the-new-tool&lang=en Tue, 24 Mar 2026 00:00:00 GMT How a new AWS WAF-based maintenance-mode tool simplified architecture, removed DNS delays, and made allowlist management safer. https://www.formoseaniap.com/engineer/article.html?id=technical-devops-sre-diaries-p0-incidents-site-unaccessible-but-accessible-part-2-dns-background-and-root-cause&lang=en https://www.formoseaniap.com/engineer/article.html?id=technical-devops-sre-diaries-p0-incidents-site-unaccessible-but-accessible-part-2-dns-background-and-root-cause&lang=en Tue, 24 Mar 2026 00:00:00 GMT A DNS primer and root-cause analysis of how a name server change made the same site appear both down and still reachable. https://www.formoseaniap.com/engineer/article.html?id=technical-devops-sre-diaries-building-a-reliable-maintenance-mode-part-2-the-legacy-system&lang=en https://www.formoseaniap.com/engineer/article.html?id=technical-devops-sre-diaries-building-a-reliable-maintenance-mode-part-2-the-legacy-system&lang=en Tue, 24 Mar 2026 00:00:00 GMT A breakdown of the legacy maintenance-mode design, including DNS delays, duplicated infrastructure, and brittle ALB allowlist rules. https://www.formoseaniap.com/engineer/article.html?id=technical-devops-sre-diaries-p0-incidents-site-unaccessible-but-accessible-part-1-incident-alarm&lang=en https://www.formoseaniap.com/engineer/article.html?id=technical-devops-sre-diaries-p0-incidents-site-unaccessible-but-accessible-part-1-incident-alarm&lang=en Tue, 24 Mar 2026 00:00:00 GMT A P0 incident story that begins with every Pingdom node reporting downtime while the site still appears reachable from the team side. https://www.formoseaniap.com/engineer/article.html?id=technical-devops-sre-diaries-building-a-reliable-maintenance-mode-part-1-introduction-and-requirements&lang=en https://www.formoseaniap.com/engineer/article.html?id=technical-devops-sre-diaries-building-a-reliable-maintenance-mode-part-1-introduction-and-requirements&lang=en Tue, 24 Mar 2026 00:00:00 GMT An introduction to why maintenance mode matters in production systems and the operational requirements behind a reliable maintenance workflow. https://www.formoseaniap.com/engineer/article.html?id=devops-sre-deep-dive-fine-grained-pod-security-in-eks-using-security-groups-part-3-pod&lang=en https://www.formoseaniap.com/engineer/article.html?id=devops-sre-deep-dive-fine-grained-pod-security-in-eks-using-security-groups-part-3-pod&lang=en Fri, 18 Jul 2025 00:00:00 GMT Following Part 2, now that your nodes are configured with Trunk ENIs, let’s test how EKS assigns Branch ENIs with custom security groups https://www.formoseaniap.com/engineer/article.html?id=devops-sre-deep-dive-pod-security-in-eks-using-security-groups-part-2-infrastructure-validation&lang=en https://www.formoseaniap.com/engineer/article.html?id=devops-sre-deep-dive-pod-security-in-eks-using-security-groups-part-2-infrastructure-validation&lang=en Fri, 20 Jun 2025 00:00:00 GMT EKS Pod-level Security: Setup Trunk ENIs, Validate Configuration https://www.formoseaniap.com/engineer/article.html?id=devops-sre-deep-dive-fine-grained-pod-security-in-eks-using-security-groups-part-1-concepts&lang=en https://www.formoseaniap.com/engineer/article.html?id=devops-sre-deep-dive-fine-grained-pod-security-in-eks-using-security-groups-part-1-concepts&lang=en Thu, 15 May 2025 00:00:00 GMT Assign unique security groups to EKS pods for tighter control. https://www.formoseaniap.com/engineer/article.html?id=understanding-eks-pod-ip-allocation-and-eni-mechanism&lang=en https://www.formoseaniap.com/engineer/article.html?id=understanding-eks-pod-ip-allocation-and-eni-mechanism&lang=en Fri, 18 Apr 2025 00:00:00 GMT This article breaks down how Amazon EKS assigns IP addresses to Pods using Elastic Network Interfaces (ENIs) on EC2 nodes. https://www.formoseaniap.com/engineer/article.html?id=handling-system-outages-caused-by-high-traffic-incidents-on-aws-ch-8&lang=en https://www.formoseaniap.com/engineer/article.html?id=handling-system-outages-caused-by-high-traffic-incidents-on-aws-ch-8&lang=en Sat, 22 Feb 2025 00:00:00 GMT Discusses strategies to stabilize system performance under high load via redeployments, caching, and automated resource management. https://www.formoseaniap.com/engineer/article.html?id=handling-system-outages-caused-by-high-traffic-incidents-on-aws-ch-7&lang=en https://www.formoseaniap.com/engineer/article.html?id=handling-system-outages-caused-by-high-traffic-incidents-on-aws-ch-7&lang=en Sat, 18 Jan 2025 00:00:00 GMT System instability recurred during a new baseball season, highlighting database issues, connection imbalance, and RDS Proxy load balancing https://www.formoseaniap.com/engineer/article.html?id=handling-system-outages-caused-by-high-traffic-incidents-on-aws-ch-6&lang=en https://www.formoseaniap.com/engineer/article.html?id=handling-system-outages-caused-by-high-traffic-incidents-on-aws-ch-6&lang=en Wed, 01 Jan 2025 00:00:00 GMT This article explains Redis monitoring, differentiates CPU types, highlights EngineCPU’s importance, and proposes alerting strategies. https://www.formoseaniap.com/engineer/article.html?id=handling-system-outages-caused-by-high-traffic-incidents-on-aws-ch-5&lang=en https://www.formoseaniap.com/engineer/article.html?id=handling-system-outages-caused-by-high-traffic-incidents-on-aws-ch-5&lang=en Sun, 01 Dec 2024 00:00:00 GMT High CPU usage on the ElastiCache server led to the discovery of a misconfiguration. https://www.formoseaniap.com/engineer/article.html?id=handling-system-outages-caused-by-high-traffic-incidents-on-aws-ch-4&lang=en https://www.formoseaniap.com/engineer/article.html?id=handling-system-outages-caused-by-high-traffic-incidents-on-aws-ch-4&lang=en Sat, 19 Oct 2024 00:00:00 GMT We delve into the journey of moving from a short-term solution to a more sustainable, long-term approach by integrating a cache mechanism. https://www.formoseaniap.com/engineer/article.html?id=handling-system-outages-caused-by-high-traffic-incidents-on-aws-ch-3&lang=en https://www.formoseaniap.com/engineer/article.html?id=handling-system-outages-caused-by-high-traffic-incidents-on-aws-ch-3&lang=en Sat, 28 Sep 2024 00:00:00 GMT We dive into the complexities and challenges encountered during system tuning and load balancing in a high-traffic baseball event. https://www.formoseaniap.com/engineer/article.html?id=handling-system-outages-caused-by-high-traffic-incidents-on-aws-ch-2&lang=en https://www.formoseaniap.com/engineer/article.html?id=handling-system-outages-caused-by-high-traffic-incidents-on-aws-ch-2&lang=en Thu, 19 Sep 2024 00:00:00 GMT The system bottleneck is the low scaling speed of our database. Two short-term strategies were developed for backend and database servers. https://www.formoseaniap.com/engineer/article.html?id=handling-system-outages-caused-by-high-traffic-incidents-on-aws-ch-1&lang=en https://www.formoseaniap.com/engineer/article.html?id=handling-system-outages-caused-by-high-traffic-incidents-on-aws-ch-1&lang=en Sun, 25 Aug 2024 00:00:00 GMT This is a two-year-long operational challenge, focusing on how to handle unpredictable high-traffic incidents on AWS. https://www.formoseaniap.com/engineer/article.html?id=a-complete-beginner-guide-for-cache-penetration-stampede-avalanche&lang=en https://www.formoseaniap.com/engineer/article.html?id=a-complete-beginner-guide-for-cache-penetration-stampede-avalanche&lang=en Sun, 27 Mar 2022 00:00:00 GMT In this article, I introduce three most famous cache issues and how to deal with them with real implementations. https://www.formoseaniap.com/engineer/article.html?id=using-nginx-as-load-balancer-with-node-js-express&lang=en https://www.formoseaniap.com/engineer/article.html?id=using-nginx-as-load-balancer-with-node-js-express&lang=en Sat, 26 Mar 2022 00:00:00 GMT In this article, I introduce the basic idea of load balancing with Nginx.