I built in the C# programming language a networked system that could replace a legacy networking system for a game that had been terminated a year prior (GameSpy). This worked well, with a peak of 2,100 concurrent users online, 2,700 user profiles (N.B. multiple profiles could be linked to a single email address, so this is not a measure of unique users), and 15 different community gameservers utilising the system.
This has been by far my largest, most complicated, and most lengthily project (2014 – 2021) and what started as a small system for a bunch of friends blossomed into a large (compared to the size of the then-playerbase) internationally-available system.
In September 2018, the system has processed an estimated 2.1b client queries, consumed 5.2TB (estimated) of bandwidth, and had 2,564 registered users worldwide.
Due to a decline in users the system was shut down in February of 2021.
Source code unavailable (proprietary code where releasing could create a security risk).