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강해수

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Joined on Jun 13, 2026

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1024-token RAG chunks cut my storage cost in half — and nearly doubled my Claude bill

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1024-token RAG chunks cut my storage cost in half — and nearly doubled my Claude bill

#ai #aiagents #mcp #cloudflare

2 min read

My Durable Object processed 4 req/s instead of 40 — the culprit wasn't storage

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My Durable Object processed 4 req/s instead of 40 — the culprit wasn't storage

#cloudflare #serverless #webdev #tutorial

2 min read

Adding one field to Notion cost me 2.5 hours. The same change in Tana took 30 seconds.

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Adding one field to Notion cost me 2.5 hours. The same change in Tana took 30 seconds.

#productivity #ai #workflow #knowledgework

2 min read

My best-looking ROAS campaigns were quietly destroying subscription revenue

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My best-looking ROAS campaigns were quietly destroying subscription revenue

#marketing #d2c #paidads #analytics

2 min read

My agent dry-ran fine in staging 100 times — then wrecked production on the first real run

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My agent dry-ran fine in staging 100 times — then wrecked production on the first real run

#ai #aiagents #mcp #cloudflare

2 min read

`wrangler dev --remote` silently writes to your production KV namespace — here's the fix

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`wrangler dev --remote` silently writes to your production KV namespace — here's the fix

#cloudflare #serverless #webdev #tutorial

2 min read

I audited 340 reading captures. Only 20% ever became knowledge I actually used.

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I audited 340 reading captures. Only 20% ever became knowledge I actually used.

#productivity #ai #workflow #knowledgework

2 min read

Adding more Claude subagents made my pipeline slower — here's the specific reason why

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Adding more Claude subagents made my pipeline slower — here's the specific reason why

#ai #aiagents #mcp #cloudflare

2 min read

56% of my notes died before I ever had a chance to retrieve them

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56% of my notes died before I ever had a chance to retrieve them

#productivity #ai #workflow #knowledgework

2 min read

My Anthropic bill dropped from 312ドル to 156ドル after I added two bash hooks to Claude Code

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My Anthropic bill dropped from 312ドル to 156ドル after I added two bash hooks to Claude Code

#ai #aiagents #mcp #cloudflare

2 min read

800 simultaneous Workers, one cache miss, 40ドル/mo surprise — the Cloudflare coalescing fix

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800 simultaneous Workers, one cache miss, 40ドル/mo surprise — the Cloudflare coalescing fix

#cloudflare #serverless #webdev #tutorial

2 min read

73% of my context switches came from one mistake: sharing a workspace across two businesses

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73% of my context switches came from one mistake: sharing a workspace across two businesses

#productivity #ai #workflow #knowledgework

2 min read

Naver Powerlink quality score: 11 of 17 ad groups flipped from medium high — here's what actually moved them

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Naver Powerlink quality score: 11 of 17 ad groups flipped from medium high — here's what actually moved them

#marketing #d2c #paidads #analytics

2 min read

D1 Schema Migrations with AI Agents: The DDL-in-Transaction Trap That Kills Zero-Downtime Deploys

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D1 Schema Migrations with AI Agents: The DDL-in-Transaction Trap That Kills Zero-Downtime Deploys

#ai #aiagents #mcp #cloudflare

2 min read

I tagged 34 decision notes in Obsidian over 18 months. Reading them back broke my Notion setup.

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I tagged 34 decision notes in Obsidian over 18 months. Reading them back broke my Notion setup.

#productivity #ai #workflow #knowledgework

2 min read

Adding one field to our CAPI payload moved match rate from 66% to 79% overnight

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Adding one field to our CAPI payload moved match rate from 66% to 79% overnight

#marketing #d2c #paidads #analytics

2 min read

A one-line cache key bug cost me 187ドル/month and leaked advertiser data across tenants

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A one-line cache key bug cost me 187ドル/month and leaked advertiser data across tenants

#ai #aiagents #mcp #cloudflare

2 min read

My Durable Objects alarm loop burned CPU for 3 days before I noticed — here's what the docs miss

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My Durable Objects alarm loop burned CPU for 3 days before I noticed — here's what the docs miss

#cloudflare #serverless #webdev #tutorial

2 min read

ASC burned ₩3M in 72 hours on out-of-stock SKUs — here's the structural fix

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ASC burned ₩3M in 72 hours on out-of-stock SKUs — here's the structural fix

#marketing #d2c #paidads #analytics

2 min read

Cutting Claude API Costs in Half with a 3-Tier Routing System (Haiku/Sonnet/Opus)

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Cutting Claude API Costs in Half with a 3-Tier Routing System (Haiku/Sonnet/Opus)

#ai #aiagents #mcp #cloudflare

2 min read

FTS5 on Cloudflare D1 cut my Korean keyword search from 220ms to 22ms — here's what almost broke it

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FTS5 on Cloudflare D1 cut my Korean keyword search from 220ms to 22ms — here's what almost broke it

#cloudflare #serverless #webdev #tutorial

2 min read

tCPA thrashed for 35 days straight — then beat manual CPC by 35% on cold prospecting

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tCPA thrashed for 35 days straight — then beat manual CPC by 35% on cold prospecting

#marketing #d2c #paidads #analytics

2 min read

60% of My 312ドル Anthropic Bill Came From One Missing Pattern: Compensating Actions

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60% of My 312ドル Anthropic Bill Came From One Missing Pattern: Compensating Actions

#ai #aiagents #mcp #cloudflare

2 min read

KV locks for Workers cron jobs will silently fail — here's what I use instead

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KV locks for Workers cron jobs will silently fail — here's what I use instead

#cloudflare #serverless #webdev #tutorial

2 min read

My 7-step prompt chain failed silently at step 6. Here's what replaced it.

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My 7-step prompt chain failed silently at step 6. Here's what replaced it.

#productivity #ai #workflow #knowledgework

2 min read

1,400 rows broke my D1 batch — here's why 7 statements beat 1,400

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1,400 rows broke my D1 batch — here's why 7 statements beat 1,400

#cloudflare #serverless #webdev #tutorial

2 min read

31% of my week was spent figuring out what I was supposed to be doing

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31% of my week was spent figuring out what I was supposed to be doing

#productivity #ai #workflow #knowledgework

2 min read

Funnel-stage ad structure collapses under budget cuts. Product-line holds longer — here's the failure mode for each.

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Funnel-stage ad structure collapses under budget cuts. Product-line holds longer — here's the failure mode for each.

#marketing #d2c #paidads #analytics

2 min read

60% of My 312ドル Anthropic Bill Came From One Silent Loop — Here's How I Found It

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60% of My 312ドル Anthropic Bill Came From One Silent Loop — Here's How I Found It

#ai #aiagents #mcp #cloudflare

2 min read

400 ad accounts 3 subrequests = silent data loss in Cloudflare Workers (and how I fixed it)

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400 ad accounts 3 subrequests = silent data loss in Cloudflare Workers (and how I fixed it)

#cloudflare #serverless #webdev #tutorial

2 min read

I lost a client note to iCloud sync conflicts — here's the Obsidian mobile workflow I rebuilt after

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I lost a client note to iCloud sync conflicts — here's the Obsidian mobile workflow I rebuilt after

#productivity #ai #workflow #knowledgework

2 min read

The Meta exclusion layer most accounts skip is costing them 8-15% of lookalike impressions

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The Meta exclusion layer most accounts skip is costing them 8-15% of lookalike impressions

#marketing #d2c #paidads #analytics

2 min read

I let Claude Code run --dangerously-skip-permissions on my production DB. Here's what I changed.

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I let Claude Code run --dangerously-skip-permissions on my production DB. Here's what I changed.

#ai #aiagents #mcp #cloudflare

2 min read

I tracked every async writing block for 90 days. Output nearly doubled — but not how I expected.

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I tracked every async writing block for 90 days. Output nearly doubled — but not how I expected.

#productivity #ai #workflow #knowledgework

2 min read

The NOT NULL trap that killed my Cloudflare Worker at 2:47am

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The NOT NULL trap that killed my Cloudflare Worker at 2:47am

#cloudflare #serverless #webdev #tutorial

2 min read

My second brain cost me 140+ hours before it saved me anything

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My second brain cost me 140+ hours before it saved me anything

#productivity #ai #workflow #knowledgework

2 min read

Naver Brand Search shows 5 –9 LTV:CAC and it's the least useful number on my dashboard

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Naver Brand Search shows 5 –9 LTV:CAC and it's the least useful number on my dashboard

#marketing #d2c #paidads #analytics

2 min read

More parallel subagents made my pipeline slower. Here's the data.

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More parallel subagents made my pipeline slower. Here's the data.

#ai #aiagents #mcp #cloudflare

2 min read

Your R2 presigned URL has a shorter TTL than you think — here's why

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Your R2 presigned URL has a shorter TTL than you think — here's why

#cloudflare #serverless #webdev #tutorial

2 min read

I tracked every context switch across two businesses for 90 days. The 23-minute recovery rule is misleading.

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I tracked every context switch across two businesses for 90 days. The 23-minute recovery rule is misleading.

#productivity #ai #workflow #knowledgework

2 min read

40% of my lookalike rebuilds were unnecessary — here's the signal-triggered system I use instead

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40% of my lookalike rebuilds were unnecessary — here's the signal-triggered system I use instead

#marketing #d2c #paidads #analytics

2 min read

My agent was 'succeeding' on Slack while silently doing nothing — here's the monitoring stack that caught it

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My agent was 'succeeding' on Slack while silently doing nothing — here's the monitoring stack that caught it

#ai #aiagents #mcp #cloudflare

2 min read

D1 read replicas returned stale data for 6 seconds — here's what I measured and how I designed around it

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D1 read replicas returned stale data for 6 seconds — here's what I measured and how I designed around it

#cloudflare #serverless #webdev #tutorial

2 min read

I tracked AI rewrite rates for 12 weeks. Notion AI needed fixing 70% of the time. Claude: 30%.

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I tracked AI rewrite rates for 12 weeks. Notion AI needed fixing 70% of the time. Claude: 30%.

#productivity #ai #workflow #knowledgework

2 min read

25–35% of our best customers were aging out of retargeting before we ever showed them an ad

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25–35% of our best customers were aging out of retargeting before we ever showed them an ad

#marketing #d2c #paidads #analytics

2 min read

I cut my Claude system prompt from 4,200 to 820 tokens to save money. It broke production in 3 days.

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I cut my Claude system prompt from 4,200 to 820 tokens to save money. It broke production in 3 days.

#ai #aiagents #mcp #cloudflare

2 min read

My weekly review clocked 14 minutes median — here's the one structural change that made it stick

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My weekly review clocked 14 minutes median — here's the one structural change that made it stick

#productivity #ai #workflow #knowledgework

2 min read

A Merchant Center disapproval wiped 40% of our SKUs the day a 6-week promo launched

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A Merchant Center disapproval wiped 40% of our SKUs the day a 6-week promo launched

#marketing #d2c #paidads #analytics

2 min read

I wasted 43ドル rebuilding a Vectorize index the wrong way — here's the 5ドル.50 fix

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I wasted 43ドル rebuilding a Vectorize index the wrong way — here's the 5ドル.50 fix

#ai #aiagents #mcp #cloudflare

2 min read

I tracked 34 'dead opens' in Obsidian over 3 weeks. That's why I switched to Tana.

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I tracked 34 'dead opens' in Obsidian over 3 weeks. That's why I switched to Tana.

#productivity #ai #workflow #knowledgework

2 min read

Naver catalog quality score: the field that tanked impression share wasn't the one we were optimizing

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Naver catalog quality score: the field that tanked impression share wasn't the one we were optimizing

#marketing #d2c #paidads #analytics

2 min read

A Durable Object I thought was idle cost me 40ドル/mo — here's exactly why

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A Durable Object I thought was idle cost me 40ドル/mo — here's exactly why

#cloudflare #serverless #webdev #tutorial

2 min read

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