Currently, we don’t have a public roadmap page. Zach Holman of GitHub (who also doesn’t publish their roadmap) explains the reasoning well in this post.
Our roadmap changes constantly, and it’s not uncommon that we end up scraping a feature we were working on just before launching, even after several months of work because we realize for one reason or another it’s not the right thing to build after all.
We previously had bad experiences with letting our customers down by promising too much and then failed to deliver on those promises. For now, our perspective (like GitHub’s) is that it’s better to surprise and delight. We strive to underpromise and overdeliver.