The program in ingester ingests crash pings, symbolicates them (locally), and outputs the resulting information and crash ping signatures. It does so as quickly as possible with the resources provisioned (you may limit threads, cache size, download count, etc).
Anecdotally, on an i9 system with a 20GB symbolication cache, this takes 45 minutes to do the same work that takes about 7 hours with the old crash ping ingestion scripts (which use the symbolication server).
date_version_config.py figures out the channel versions for a given date
and reads the REDASH_API_KEY environment variable to output configuration for the ingester (which
can be piped in stdin).
reports_on_demand_crash_ids.py reads processed ping output from the ingester as file arguments and will choose crash ids to be sent through Remote Settings to get more reports for particular signatures. It checks Socorro to determine whether particular signatures need reports or not.
The taskcluster tasks are configured such that, when started as a cron job, ping data is processed for any days in the past 7 days which don't yet have processed data. The goal is to have ingested data for as much of history as possible, however we allow a 7-day buffer in case the CI is broken (from internal or external factors), with the assumption that it will be repaired within that window. If specific data is missing, the task can be manually run: there is an action on the task group to manually run for a given date).