At SmartX, we are deploying and managing tens of nodes for delivering content everywhere in the world. We are writing code which supports a heavy traffic, highly available, fast loading, live streaming web site.
Behind this main product there are many projects using APIs developed to help our clients to integrate them fast and easy: live streaming projects, payment platforms, games, chat, VR and mobile apps, data warehouse.
Behind the words are figures:

website access in a day: average sessions per day: 1,075,700
visitors: average unique users / day: 20,627; average repeated users / day: 1,362,666
page requests per device type: average mobile access:1,064,832; average tablet access:123,150; average pc access:2,338,697; average others access:2,065
live streaming is live: delay of 0.5 seconds is huge!

How we achieve that? The secret is on architecture and in technologies. So here you are:

Streaming is essential, and we are able to handle HLS, webRTC, flash, MBA, VR with ABR and webGL from PC or from mobile (Android, iOS). All mandatory being real time.
Architecture is a mix of SOA systems and microservices, all API based.
Cloud distribution is the key for high availability. And here our DevOps are coming with Docker, Kubernetes, Spinnaker. This way they can manage hundreds of pods in 5 data centers serving any corner of the world.
And maybe most protected secret is (don’t tell anyone) we have our own mad scientists working on big data and doing their magic (don’t ask me how they made it).

Who is doing all these? The secret is not technology, or architecture, or the line of code. The secret is: People. People like everyone. But they are willing to think fast, to move fast and to react fast. Even pursuing our quarterly OKR, they are choosing their technologies and design, they are constantly looking for how to make work more efficient. And, quite often, even fun. Because we are not a corporate, we are real Agile team. In many, if not all, senses.