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Around 2012-2013 I was working on an online education platform. We had a whole web application that would serve video content, collect student answers and analyze in real-time(ish) the student progress in order to find out the next action for the student - e.g, if the student starts to get questions wrong that they were getting right before, we'd take it as a sign of fatigue and would recommend them to take a break. Or if the student was showing that has mastered a topic, we would jump ahead in the lesson to something else that needed more work. So we needed a web server, a database, a queue system to run these heuristics and we needed to host/distribute ~100GB worth of content, most of it video. We were bootstrapping, so I was trying to (1) save as much as possible on operational costs and (2) punt on all the "scaling issues" that would require more of my devops time that would be better spent developing and adding more features. I deployed the whole system on a single server from Hetzner: Django app, Postgresql, Redis for caching and session management, RabbitMQ for celery. All in one machine with 32GB of RAM and a RAID system with enough capacity to hold the data. I think it was costing us less than 50€/month. That is all we needed to (easily) serve ~800 students and the staff who would author new content. In the end we delivered everything we promised to our first customer, but we were not able to grow our revenue as much as we expected, so by end of 2013 we just put the whole company on the backburner, got a small maintenance contract with the main customer and went on to find another jobs. From end-2013 until 2018, I needed only to make sure that our domains and SSL certificates were up-to-date every six months, upgrade django packages in case of security issues and deal with ONE incident (in 2016 IIRC) where a disk failure put the array in degraded mode, which I solved by getting a new server at Hetzner (better specs and cheaper, after all those years), warning the customer that the service would be taken offline for a couple of hours later in the day, rsyncing the content, restoring the database and redeploying the application with the fabric script. This is one the projects that I am most proud of what was accomplished given all the constraints and made me realize the difference between a Software Developer and an Engineer. Yet, it translates to a very poor entry on an CV. We are too used to ask on interviews what people have done and what technologies they have used, but we rarely ask about the moments where it was best to avoid doing something. |