--- title: "Hayrullah Kar (@magesheet) | Hashnode" description: "Founder & Automation Strategist @MageSheet | Google Apps Script & AI Specialist. Read the latest articles by Hayrullah Kar on Hashnode." url: "https://hashnode.com/@magesheet" --- @magesheet # Hayrullah Kar @magesheet · Sakarya,Turkey · Joined May 2026 Founder & Automation Strategist @MageSheet | Google Apps Script & AI Specialist. [Website](https://magesheet.com/) ### [Outgrown Google Sheets? Count the Slow Formulas Before You Decide](https://magesheet-team.hashnode.dev/outgrown-google-sheets-formula-audit-apps-script?utm_source=hashnode&utm_medium=feed) One Apps Script function counts NOW(), A:A ranges and IMPORTRANGE in every tab and writes a Sheet health report. Testing it also found three inputs our locked recordSale() let through. 12 min read · [magesheet-team.hashnode.dev](https://magesheet-team.hashnode.dev/outgrown-google-sheets-formula-audit-apps-script?utm_source=hashnode&utm_medium=feed) [2d ago](https://hashnode.com/posts/outgrown-google-sheets-formula-audit-apps-script/6aef5092740d55cd99e290c9) ### [Build vs Buy in Google Sheets: The Break-Even Cell That Said -400 Months](https://magesheet-team.hashnode.dev/build-vs-buy-break-even-google-sheets?utm_source=hashnode&utm_medium=feed) B / (S - R - M) is the right formula. In a sheet it returns -400 when upkeep eats the saving, and it holds the subscription flat for three years. Three custom functions fix both. 11 min read · [magesheet-team.hashnode.dev](https://magesheet-team.hashnode.dev/build-vs-buy-break-even-google-sheets?utm_source=hashnode&utm_medium=feed) [2](https://hashnode.com/posts/build-vs-buy-break-even-google-sheets/6aecc4134175d3022d7bdd99) [4d ago](https://hashnode.com/posts/build-vs-buy-break-even-google-sheets/6aecc4134175d3022d7bdd99) ### [Apps Script Error Handling: The Failed Invoice Your Ledger Skips Forever](https://magesheet-team.hashnode.dev/apps-script-failed-retry-ledger-watchdog?utm_source=hashnode&utm_medium=feed) Run against fakes, the guide's retry ledger skipped a send that threw on every later run: 0 invoices sent, heartbeat ok. A failed state, a retry limit and a watchdog with memory fix it. 12 min read · [magesheet-team.hashnode.dev](https://magesheet-team.hashnode.dev/apps-script-failed-retry-ledger-watchdog?utm_source=hashnode&utm_medium=feed) [Nov 1](https://hashnode.com/posts/apps-script-failed-retry-ledger-watchdog/6ae73cbe21d3303efa05a8a0) ### [Google Workspace Offboarding: A Dry Run That Survives a Failed Step](https://magesheet-team.hashnode.dev/workspace-offboarding-dry-run-resume?utm_source=hashnode&utm_medium=feed) Run against a fake Admin SDK, the plan-then-apply offboarding script could not finish after one transient error, wiped a phone twice, and ignored a row the reviewer deleted. Moving the plan into the sheet fixes all three. 13 min read · [magesheet-team.hashnode.dev](https://magesheet-team.hashnode.dev/workspace-offboarding-dry-run-resume?utm_source=hashnode&utm_medium=feed) [Oct 28](https://hashnode.com/posts/workspace-offboarding-dry-run-resume/6ae1947284c79ec38b967bbf) ### [WhatsApp Response Time in Google Sheets: The Webhook Can't Tell Your Bot From Your Agent](https://magesheet-team.hashnode.dev/whatsapp-response-time-in-google-sheets-the-webhook-can-t-tell-your-bot-from-your-agent?utm_source=hashnode&utm_medium=feed) Run on fake events, the usual webhook-to-Sheets code logs a 2-second bot acknowledgement and a 10-minute agent reply as identical rows. Tag every outgoing message, and count business minutes. 14 min read · [magesheet-team.hashnode.dev](https://magesheet-team.hashnode.dev/whatsapp-response-time-in-google-sheets-the-webhook-can-t-tell-your-bot-from-your-agent?utm_source=hashnode&utm_medium=feed) [Oct 26](https://hashnode.com/posts/whatsapp-response-time-in-google-sheets-the-webhook-can-t-tell-your-bot-from-your-agent/6adf104fa412e85d1ebd0847)