Following the official guide
imports/
startup/
client/
index.js # import client startup through a single index entry point
routes.js # set up all routes in the app
useraccounts-configuration.js # configure login templates
server/
fixtures.js # fill the DB with example data on startup
index.js # import server startup through a single index entry point
api/
lists/ # a unit of domain logic
server/
publications.js # all list-related publications
publications.tests.js # tests for the list publications
lists.js # definition of the Lists collection
lists.tests.js # tests for the behavior of that collection
methods.js # methods related to lists
methods.tests.js # tests for those methods
ui/
components/ # all reusable components in the application
# can be split by domain if there are many
layouts/ # wrapper components for behaviour and visuals
pages/ # entry points for rendering used by the router
client/
main.js # client entry point, imports all client code
server/
main.js # server entry point, imports all server code