On 31 October I took part in the preliminary round of Kakao's AI TOP 100, where an AI agent is built and submitted within five hours, and I submitted just before the deadline. Leaving the problem itself out, this note covers how I split the work with two AI tools, what went well, the material that came after the last deploy, running short of credit, what testing in the real channel showed, and nine things I will change next time.
In SAP documentation the valid rate is one entered on that date or earlier, so with no row for today a foreign currency document still posts if an earlier type M rate exists. Using a fictional invoice, this note calculates how the amount changes with posting and translation dates, then covers quotations, rates entered by hand and how to find stale rates, based on the S/4HANA 2025 documentation.
A search for C++ reached the server as C followed by two spaces. In a query string, + means a space only to functions that read the form format; to percent-encoding functions such as encodeURIComponent and decodeURIComponent it is just a +. Using real runs on Node.js v24.21.0 and Python 3.9.6, this note shows how to pair the function that writes a query with the one that reads it so that + signs and spaces come back intact.
Korean household credit at the end of June 2026 was 25.9 trillion won above the end of March, yet the household debt-to-GDP ratio fell from 85.3% at the end of March to 81.1%. Recompute the ratio from public statistics and split its fall between debt and GDP.
Node.js 24 runs a TypeScript file directly with node app.ts, but it only blanks out the types and never checks them. Real runs on Node.js v24.21.0 show code with the wrong types printing 1000100 and exiting with 0, an enum and an interface imported without type failing with a SyntaxError, and a tsconfig.json paths alias being ignored. The note then sets out how to hand type checking to tsc as a separate step.