Bid Info Watch

Overview

Daily crawler scans Yokohama city bid announcements, matches 11 cleaning/building-maintenance keywords, and notifies subscribers via email or LINE. Double opt-in, one-click unsubscribe, automatic unsubscribe on SES bounce/complaint, and a honeypot field ensure deliverability and compliance. LINE notifications use a LIFF flow that combines friend-add and account linking in one screen, with webhook-driven auto-unsubscribe on block. Stripe webhooks reconcile payment status with subscriber records, and the site includes required Japanese commercial-transaction-law disclosures. Solo-run pilot service currently validating demand in Yokohama city alone.

Architecture

Key Implementation Points

• Double opt-in, one-click unsubscribe, and automatic unsubscribe on SES bounce/complaint balance compliance and deliverability
• Added LINE as a parallel notification channel; a LIFF flow combines friend-add and account linking in one screen, with webhook-driven auto-unsubscribe on block
• Stripe webhooks with self-verified HMAC signatures reconcile checkout/cancellation events against subscriber records automatically
• Daily crawler scans the Yokohama city bid site, filters matches against 11 cleaning/maintenance keywords, and enriches notifications with eligibility and deadline details pulled from detail pages

Tech Stack