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Hello! 
I’m Jeongil Jeong, Backend Developer

Sharing my development journey through honest documentation of challenges faced, solutions found, and lessons learned. Thank you for visiting.

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Recent Posts

API Performance P95 7s → 0.1s Backend Optimization — Finding the Bottleneck Was Harder Than Fixing It

Hi, I’m Jeongil Jeong, a backend developer working at a proptech platform. One day, as usual, I was checking the Grafana dashboard for monitoring. The average response times were mostly within a few h...

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March 4, 2026

CI Took 45 Minutes After Switching to Modular Monolith - Optimizing Our Spring Test Pipeline by 77%

Hi, I’m Jeongil Jeong, a backend developer working at a proptech platform. In a previous post, I wrote about how I, as the sole remaining backend developer, consolidated 13 microservices into a modula...

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February 27, 2026

MSA Was Too Much for Us - Our Journey to Modular Monolith

Hello. I’m Jeongil Jeong, a backend developer working at a proptech platform. Our company had successfully completed a zero-downtime migration from a legacy Java Servlet monolithic service to MSA and ...

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February 20, 2026

The Ever-Changing AI Coding Agent Ecosystem: oh-my-opencode, oh-my-claudecode, OpenClaw, Agent Teams

Hello. I’m Jeongil Jeong, a 3rd-year backend developer working at a proptech platform. The AI coding tool ecosystem has been changing incredibly fast lately. A tool that was trending a few days ago ge...

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February 9, 2026

3AM Error Alerts? Let AI Fix Them: Automating Error Response with OpenClaw

Hi, I’m Jeongil Jeong, a 3-year backend developer working at a proptech platform. TL;DR I automated 3AM error alert responses with OpenClaw. Using Loki/Tempo polling + Telegram Forward hybrid appr...

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February 6, 2026