Ask HN: How to Built an Active Community

I have built the Tech Content Platform Insidestack (https://insidestack.it) as a new side hustle with currently over 1000 popular RSS Feeds from independent tech experts, tech media houses and Big Tech.

The site has some nice features like - Semantic search with text embedding - You can block / follow feeds - You can bookmark and comment articles

The longterm goal is that any user can build customised feeds by defining interests (which translate into search vectors).

I think the site has clean, modern design and is also quite efficient. (warning not vibe-coded). It is fully self-hosted from frontend, backend, database and email.

The costs are extremely low currently, I spend less than €20 / month. I want to offer this as completely free service, not even requiring registration, except for creating customised feeds.

My question is what is the best strategy to build an active community. I was thinking of open sourcing the feeds to get some attention. But this would be yet another awesome list... I was also occasionally posting on Reddit but this has very short-term effect...

Looking forward to your suggestions.