Recently, I was back at the Cloud Native London meetup, having been given the opportunity to present due to a speaker canceling at the last minute.
This group has 7,000+ members and is, "...the official Cloud Native Computing Foundation (CNCF) Meetup group dedicated to building a strong, open, diverse developer community around the Cloud Native platform and technologies in London." You can also find them on their own Slack channel, so feel free to drop in for a quick chat if you like.