PPowerduckinblogs.powerduck.com·8h ago · 3 min readThe Agent Converted the If/Else Chain to a Lookup Map and Dropped the Side EffectThere is a function in almost every backend that maps an internal status code to a user-facing message. It starts as a tidy if/else block, and over the years someone has bolted on logging, metrics, an02YV
PPowerduckinblogs.powerduck.com·9h ago · 3 min readThe Agent Added an Await to a Synchronous Function. The Caller Didn't Notice.A teammate pasted a stack trace into our channel last week. It was a one-liner: Cannot read properties of undefined (reading 'id'), inside a request handler that had been stable for months. The diff t00
PPowerduckinblogs.powerduck.com·10h ago · 2 min readThe Agent Rewrote the Shell Script in Python and Dropped the Exit CodeThe build script was 40 lines of bash. It ran npm test, then npm run build, then rsync the dist folder to a server, then paged us on Slack. It worked. Nobody loved it. One morning I asked the agent to00
PPowerduckinblogs.powerduck.com·14h ago · 3 min readThe Agent Flattened Your Custom Error Type Into a Generic ErrorThe refactor looked clean. The agent took a module with three custom error classes — NotFoundError, ValidationError, RateLimitError — and replaced them with a single generic Error carrying a code stri00
PPowerduckinblogs.powerduck.com·11h ago · 4 min readThe Agent Deleted the Comment That Explained Why the Code Looks WeirdThe function looked wrong. It returned an object with a key that started with a dollar sign, it did a network call inside a loop, and it mapped one enum value to a string that didn't match the enum's 11A
ACAgentKit Coinagentkitco.hashnode.dev·11h ago · 4 min readAGENTS.md vs CLAUDE.md vs Cursor Rules: Which Do You Need?If you use an AI coding agent, you have probably been told to "write a rules file". Then you looked and found four or five different file names. This guide explains what each one is, which tools read 00
ACAgentKit Coinagentkitco.hashnode.dev·11h ago · 4 min readHow to Write an AGENTS.md That AI Coding Agents FollowAn AGENTS.md file is a README for coding agents. The format is deliberately simple: plain Markdown, no required fields, and the closest file to the code being edited takes precedence. The hard part is00
PPowerduckinblogs.powerduck.com·12h ago · 3 min readThe Agent Wrote a Test That Mocks the Function Under TestThe test file passed. The function it was supposed to cover was broken. The mock was the giveaway. CI went green. Coverage on the new module jumped to 94%. I opened the PR confident, and the first tes00
PPowerduckinblogs.powerduck.com·13h ago · 3 min readThe agent refactored that tiny function for clarity. It doubled the runtime.The PR looked great. The agent had pulled a 40-line function out of a 1200-line file, split it into three small helpers, named the variables better, and added docstrings. Every existing test passed. T00
PPowerduckinblogs.powerduck.com·15h ago · 4 min readThe agent created a new file instead of editing the existing one. Now there are two.The PR diff looks fine. You asked the agent to add a phone-number validator. It added a file called validation-helpers.ts with a clean, well-tested validatePhone() function. CI is green. The code is c00
