Technical writeups on backend development, Cloudflare Workers, API security and debugging.https://simonedimauro.comenhttps://simonedimauro.com/writeups/illegal-invocation-cloudflare-workershttps://simonedimauro.com/writeups/illegal-invocation-cloudflare-workersThe contact form answered 502 on staging, the email provider saw no request and all 57 tests were green. The cause was a single line that called fetch as a method, which the Workers runtime rejects and Node does not.Thu, 05 Nov 2026 00:00:00 GMTCloudflare WorkersTypeScriptDebuggingTestinghttps://simonedimauro.com/writeups/hardening-contact-form-cloudflare-workershttps://simonedimauro.com/writeups/hardening-contact-form-cloudflare-workersReplacing a browser-side email service with a Cloudflare Worker endpoint. Every request goes through size limits, strict validation, a honeypot, rate limiting and server-side Turnstile before a single email is sent.Wed, 04 Nov 2026 00:00:00 GMTCloudflare WorkersAPI SecurityTurnstileTypeScript