In the Dashboard for your project, you'll find a link to logs for both Test and Live servers (if they've been deployed):
Recent logs will be shown for your servers, including application messages and errors. The aim is to help you debugging recent issues with our deployments or if the site is throwing an error.
Currently logs are limited to the last 1000 logged rows. All activity will be logged, including web requests, cron job executions, Celery workers and SSH sessions.
Sometimes you want to browse logs past the 1000 entries limit. For this you need to setup your own logging tools.
To integrate, look for their Python/Django integrations and then apply the required settings to your settings.py file.