I worked mainly in startup companies. At Novom Networks, I introduced NodeJS and it quickly became the de-facto backend platform. I then started incorporating more and more AWS services in our products and our reliability and efficiency greatly increased. My proudest achievement there is probably the API I built to handle almost 1k req/s (mostly write operations). It was for a festival mobile app, and after spending a long time preparing, scaling, load-testing for the spike, the API handled it perfectly when the time came.
At Tylio, I developed everything in the beginning. I designed and setup the database and the cloud architecture in AWS, I built the whole backend API and I built the foundations for the frontend application. I also coached our intern a lot on React and JS in general, who then became a full time employee. My proudest achievement is probably the realtime, on-demand image resizing and optimization system I put together using AWS Lambda, S3 and CloudFront.
Describe the most impressive thing you've done.