One annoyance about the UI (for me at least) is the real lack of information density. Hacker News manages to show 15 stories without even scrolling, while this manages to present... 3?
For starters, individual posts in the Explore view[0] are wayyyy too big, while not providing much information at all. Look at the Comments button, for instance: why is that on a separate line?
After 5 minutes of experimentation, I was able to condense the post item down to the following: https://i.imgur.com/KthkpPQ.png While it does have some kinks, it looks much better and presents a greater amount of information in about 30% less space. Low-hanging fruit, I'd say.