Automatic archival of old groups

Old groups are archived automatically to save space in RTDB (which is expensive). This is controlled by lastChanged field of each group. This is a multi-step process.

Remind users about unsettled debts in their group

After 32 days of no activity, a reminder is sent to everyone participating in any debts in the given group. This is done by matching members to their corresponding users. Email 07_group-debt-reminder is sent, along with a push notification. The same email and notification is sent when this is triggered manually from the app (Premium feature).

The number 32 days is deliberate because users might have a monthly recurring subscription, so this is designed to not interfere with those.

Remind users their group will be archived

One week before archiving a group its users are notified this will happen. Email 08_group-archive-reminder is sent.

Archive old groups

Currently, unsettled groups older than 6 months and settled groups older than 3 months are archived. Premium groups are not archived.

This process runs several times a day to decrease the load on the database with a limit for the number of groups archived. The groups with highest lastChanged are archived first going further into the past.

When archival happens the users are notified via a push notification (regular Change is generated too).