Working on an ecommerce platform, mainly backend (rails, node), but also some front end (React).

We were in charge of getting metadata from different internal & external sources, processing it, and deliverying it (some in real time, some offline) to the proper front end & intermediate servers.

Implemented different features (like rank), worked on some efficiency algorithms, and also implemented a complete development environment to allow proper deployment, caching hard to find bugs, etc.

The systems were very multithreaded, so got the opportunity to play a lot with concurrency problems, and learn about proper practices.

Implemented detection of signals to detect bad quality Ads (blank, malware, etc). Also implemented features for our clients (mainly deeplink, which generated a new income for this quickly ongrowing market).