Pretty sweet. Are all these entries posted by companies themselves or did you do the posting? I love how it's neatly organised by language. Are you planning on adding any other layers/filters?
As-is the site is not useful to me, but it has potential. The simple layout is awesome, not cluttered but still presents a bunch of info.
Location filters are must-have - whether it's just a sort by name so all of the $MY_CITY jobs are in one place, as a true filter so I only see one location or as some kind of location-based sort-by-distance to give me the best options first.
Yes I'm planning to add City/Location filters as well as advanced search option where you can see all available filters.
There is for example also https://startupdeveloperjobs.com/f/0/Erlang but you can't see it since it has not enough jobs
Edit: To answer your other question. Jobs are both entered by companies and also added by me manually.