Lumora - Community Constellation
Inspiration
For the last decade, moderation tools have fundamentally been built to do one thing: punish bad actors. They are highly efficient dashboards designed to ban, mute, and delete. But what about the good actors? Every subreddit has a silent majority and a vocal minority. But beneath the daily feed, there are a few dozen people who actually hold the ecosystem together. They are the historians, the welcomers, the anchors. The problem is that moderators have no way of knowing who these people are until after they burn out and leave the community. We realized that preventing burnout is the ultimate form of moderation. We built Lumora to shift the paradigm: it’s time we built tools to celebrate the good ones.
What it does
Lumora is not a spreadsheet or a dashboard, it is a community memory engine. Running natively as a post inside a subreddit, Lumora maps your community's top contributors into a living, interactive constellation. Size represents a user's tenure. Brightness represents their contribution level. Moderators can enter the expanded "Mod View" to filter the constellation. By selecting the "Going Quiet" filter, active stars fade to 5% opacity, instantly revealing the "dimming stars" Community Pillars who haven't posted in weeks. When a moderator hovers over a star, they see exactly how long that person has been there, along with a quote from their very first post to remind the mod of the human behind the username. With a single click, mods can "Recognize" the user, triggering a cinematic supernova visual and natively calling the Reddit API to permanently assign them a "Community Pillar" flair.
How we built it
Lumora is built entirely on Devvit (Reddit's Developer Platform). Frontend: React 19, Tailwind CSS 4, and a custom HTML5 Canvas engine. Backend: Node.js v22 (Serverless), Hono, and Redis for data persistence. Audio: A completely programmatic Web Audio API synthesizer (zero external audio files). To solve the scale problem (subreddits with 5 million users), we designed Lumora as an O(1) sampling engine. Instead of querying massive databases on load, Lumora relies on a background CRON job that aggregates only the top 1% of active contributors over a 30-day window into Redis. We don't map the noise; we exclusively map the signal.
Challenges we ran into
The Render-Thrashing Bottleneck WebViews and iframes can heavily throttle standard DOM updates. Initially, tracking mouse movements over 200+ rendered stars caused React to run 60 massive reconciliation cycles per second, causing violent stuttering. Solution: We completely abandoned the React DOM for the visualization layer. The UI shell is built in React (wrapped in strict React.memo boundaries), but the constellation itself runs in a fully detached HTML5 Canvas requestAnimationFrame loop. This guarantees a locked 60fps experience, even on low-end hardware.
Browser Autoplay Policies We wanted the app to feel like a cinematic space engine, which required an ambient, generative audio pad. However, modern browsers silently block AudioContexts from playing without explicit user interaction. Solution: We implemented an "Audio Autoplay Guard" that invisibly binds the audio synthesizer initialization to the very first onPointerDown event inside the Canvas wrapper, guaranteeing the audio context is legally unlocked without breaking the immersion.
Accomplishments that we're proud of
We are most proud of making a utilitarian moderation tool feel like a premium, emotional experience. Data tables don't generate empathy. We proved that by using spatial design, micro animations, and auditory feedback, you can fundamentally change how a moderator feels about their community.
What we learned
We learned that the technical architecture of an app must serve its psychological goal. It wasn't enough to just render dots on a screen; the math behind the hover hitboxes, the exact 150ms entrance speed of the glassmorphic cards, and the 1.2 second "scanner" sweep animation on mount were all critical in making the app feel like a real time, living ecosystem rather than a static chart.
What's next for Lumora - Community Constellation
Our next step is operationalizing the empathy Lumora creates. We plan to expand the CRON sampling logic so subreddits can define custom parameters for what constitutes a "Pillar" in their specific niche. Finally, we want to integrate a seamless 1-click Modmail workflow, allowing moderators to instantly send a personalized "check-in" message to Dimming Stars directly from the Canvas interface.
Built With
hono
html5
node.js
react
redis
tailwind
web-audio-api
Try it out
/ comms_inprogress_dev