BUILD IN PUBLIC · Build logs

Building an AI product, written down as it ships.

Engineering retrospectives from building this solo — Backend, Frontend, AI, Infra. Translated from the Korean originals; the raw path from a broken deploy to the fix.

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Infra

Infra

0 Minutes of Downtime! Mastering Next.js Zero-Downtime Deployments with Atomic Swap

Have you experienced frequent service interruptions during Next.js deployments? This post introduces how to implement 0-minute downtime deployments using the Atomic Swap technique.

May 15, 2026·👁 378
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Infra

Infra

Google AI Studio 503 Errors? Migrated to Vertex AI and Converted 27 Files Instantly!

Experiencing frequent Google AI Studio 503 errors? I migrated to Vertex AI and successfully converted 27 files in an instant! Learn how to ensure stable service operations.

May 13, 2026·👁 173
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Backend

Backend

Blog SEO Automation in 2026: Finishing Initial Search Awareness with IndexNow Scripts

Blog SEO Automation in 2026: Finishing Initial Search Awareness with IndexNow Scripts

May 11, 2026·👁 160
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Infra

Infra

Blocking Bot Traffic with nginx + fail2ban, No Cloudflare Needed

I ran into issues with Cloudflare conflicting with SSE streaming, causing disconnections. I switched back to running a single GCP instance. Instead, I built my own scanner/bot defense line using just nginx limit_req + fail2ban + sysctl.

May 10, 2026·👁 297
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Backend

Backend

CPU at 70% with Low Traffic? My Story of Catching a Duplicate Scheduler in a 4-Worker Environment

I noticed a CPU spike to 70% in our admin monitoring. Why, with almost no traffic? The culprit turned out to be that each of our 4 gunicorn workers was running its own APScheduler instance. I implemented singleton scheduling using PostgreSQL advisory locks.

May 10, 2026·👁 154
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Frontend

Frontend

Next.js 14: `next build` `--distDir` Removed? Avoiding 5 Zero-Downtime Deployment Pitfalls

During my Next.js 14 migration, the removal of the `--distDir` flag in `next build` caused issues with zero-downtime deployments. Check out how I solved it.

May 10, 2026·👁 223
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Backend

Backend

Boosting Blog Post Visibility: Building an Automation System with the IndexNow API

A guide to automating blog post publishing with the IndexNow API. Learn how to integrate IndexNow to speed up your content's appearance in search engine results.

May 10, 2026·👁 169
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AI

AI

4 Pitfalls Discovered After Migrating from Anthropic to Gemini

I switched from Claude Sonnet 4.6 to Gemini 2.5 Flash to save 80% on costs, and encountered these real-world bugs. I hope you can avoid the same mistakes.

May 3, 2026·👁 166