Yesterday the Frontend Mentor community jumped above 3,000 members.
I created the community in October 2018 and it's grown steadily ever since.
It's been amazing to see it grow and see people helping each other out. I'm still extremely active in it reviewing people's code and offering help if people get stuck on the challenges. But it's great to know that if I'm not on it for a day or two now everyone just helps each other and cracks on with it.
Having a Slack community is also an amazing tool for product development on your platform. You see patterns start to emerge in conversations and they can give you ideas for new features. For example, a lot of people have started collaborating on the challenges in Slack. So I've done a number of user interviews and will be looking to add a collaborations feature to the platform itself as a result.
If you have a product/platform of any sort, I'd strongly recommend starting up a community, whether it's Slack or Discord. It's such a great way to build a strong relationship with the people in your community.