Back in the days of face to face conferences and golden era of paid testing conferences, we had up to 150 people come together for two days to discuss testing in Finland. Going to large international conferences, seeing audiences up to a thousand was typical. Living in the testing conferences bubble, you would meet other testers from other companies and other countries, with an occasional brave developer by trade tipping their toes into the mix.
As years passed, I started noticing that half of the speakers are usually from the same circuit, learning more and sharing more each time. People came and got started at speaking, some stayed around in the circuits, others faded away focusing on changing things from within the organizations that employ them.
Inside companies as years passed, the position of testers also changed. When in the past you could expect to find a condensed group of testers, agile sent everyone to teams and a typical team would have one specializing tester. At the same time communities of testers became even more active. Communities within companies, and communities that are connected by local or global thread emerged.
The world started to look more like this. A single tester, no other testers in sight.