India has the most severe lockdown for COVID-19 for obvious reasons, so the online grocery deliveries are working with minimum staff.
BigBasket, the leading online grocery delivery platform has introduced random slots for booking in several cities and the only way to book grocery through it is to check the app routinely at intervals(slots open up even after midnight).
To solve that, I have created a simple Go script which uses chromedp (A Chrome DevTools Protocol implementation in Go) to check for site message in BigBasket and send a push notification via Pushover when the 'Slot unavailable' message is not there[2].
[1] https://needgap.com/problems/112-alert-me-when-slots-in-bigbasket-is-open-india-ecommerce
[2] https://github.com/heavyinfo/bigbasket-slot-alert