startfile in your repo (https://repo2docker.readthedocs.io/en/latest/config_files.html#start-run-code-before-the-user-sessions-starts) you can run commands when your repo is launched
postBuildfile. or you use a data format which allows random access over the network and only read what you need when you need it
gs://pangeo-data/gpm_imerg_early, because a new version has been released and the TRMM era has been merged, so it's now available from June 2000 instead of 2014. I will also include the
probabilityLiquidPrecipitationfield, along with the
precipitationCalfield, so that we have an information about solid precipitation.
startscript. The data being downloaded though was on google's cloud storage though so I wasn't too worried about the network traffic for the ~3GB I was downloading.
startwithout putting it in the background then a similar thing will happen where binderhub will wait for jupyter lab to start up but it won't happen in time because data is taking too long to download