backpack.tf is the leading economic resource for Team Fortress 2.
Traders trust backpack.tf to supply and decide accurate pricing information in a clear and democratic voting process.
backpack.tf started as a project by Steve "Brad Pitt" Rabouin in 2012 (although the site's birthday is a little difficult to pinpoint). The project has seen some large changes since then, such as the merge of stats.tf and support for other Valve titles such as Dota 2 and Counter-Strike: Global Offensive.
We have a number of moderators who put in a lot of work to keep the price guide up-to-date. If you would like to support their efforts, you can do so here.
The backpack.tf frontend runs on PHP. There are also a couple Node.js bots going around. A small Python script is used to index items to the Elasticsearch cluster.
Our servers are located in Newark, New Jersey.
Stats are gathered by parsing inventories as they are loaded on-site. We log every new item we see to Elasticsearch, and this information is used to populate data for item histories, the Premium search system, and of course detailed statistics for each item.
There are, however, some caveats to doing this:
In other words, don't expect perfect statistics, as this is unfortunately impossible to guarantee.