---
title: "Jeongjin Shin (@jeongjin0) | Hashnode"
description: "Building small developer and productivity tools. Read the latest articles by Jeongjin Shin on Hashnode."
url: "https://hashnode.com/@jeongjin0"
---

@jeongjin0

# Jeongjin Shin

@jeongjin0 · Seoul, South Korea · Joined June 2026

Building small developer and productivity tools.

## Comments

[The oldest\_unacked\_message\_age vs raw backlog distinction is the right one to lead with, most teams alert on the wrong metric early on. On the ordering-key hot spot problem at 10x, did you consider splitting the hot key onto its own subscription instead of sharding the whole topic? That way a bursty user doesn't stall throughput for everyone else sharing the same ordering key space.](https://hashnode.com/posts/observability-and-scaling-monitoring-event-lag-and-handling-failure/6a545971410abcfd6a71df3e/comment/6a54b332bd852da48e90832f)

Comment · Article · Jul 13 · [Observability and Scaling: Monitoring Event Lag and Handling Failure](https://hashnode.com/posts/observability-and-scaling-monitoring-event-lag-and-handling-failure/6a545971410abcfd6a71df3e)