For reference, servers with 2 cores and 4GB of memory are available for roughly a dollar a day, which may be negligible for a one-day workshop with 100 participants or a tutorial week with 20, but can become expensive for long-running courses or courses that attract a very large audience. Substantial cost savings are possible with autoscaling setups like the one mentioned above which boot up extra servers only on demand (i.e. when students are actually logged in and using the hardware). And second, one great strength of the platform approachthe high level of technological abstraction it enables -can also be a weakness: when the course finishes and students lose access to the platform, they also lose access to the software without having learned how to set it up on their own hardware. Upon closer inspection, however, this is a matter of priorities: the browser-based approach simply makes the installation of software on the students' machines optional. If learning how to install the code is deemed important, it can be included as a dedicated session at a convenient stage in the course.