How to steam live video with FFmpeg with low latency?

I’m streaming live video from a camera using FFmpeg and trying to reduce end-to-end latency when playing it in a web browser.

Right now, I’m encoding h.264 and pushing the stream to a media server (I’m testing with Red5: https://www.red5.net). Playback works, but the latency is several seconds, which is too high for real-time use cases.

My current command is roughly:

ffmpeg -f v4l2 -i /dev/video0 -c:v libx264 -preset veryfast -tune zerolatency -f flv rtmp://server/live/stream

Are there recommended configurations when the goal is sub-second latency to a browser (for example when the server converts the stream to WebRTC or low-latency HLS)?