Apps at Media.net
This is at my current job at Media.net. I'm part of the team building web apps having more than a million impressions a day.
The project has a large team consisting several small sub-teams having different responsibilities.
My role in the team has been more on the front-end, with occasional changes/feature implementations on the backend. On the front-end, I got to implement complex interactive data-intensive UIs in ReactJs. On the back-end, I got introduced to nodejs and learned to use it to create services on the server-side. Also learned some PHP to make changes to some old code. MySQL as a the primary database with several Redis instances for the caching layer.
The scale in terms of number of users and code helped me understand the challenges involved in building large complex systems. I understood how efficient caching at different places can speed up our systems.
I also observed how product managers shape the products, something I was not exposed to before. At my previous work, this was something done partly by the developers. I have always been interested in the product development/product management and crucial it is to building great products.