I've heard that it's a good rule of thumb to not develop something that is just an extra feature of an existing behemoth (e.g. Atlassian plugins etc., but also the thing you built). If you're failure, then you've wasted time and money and if you're a success, the behemoth will just reimplement your work as a part of their platform.
Pretty much the only way to win it so make something that provides marginal revenue, which makes reimplementation not worth it for the giant (but potentially worth it for you). I suspect a lot of Unity and Unreal plugins and authoring tools reside in that niche.
Marginal revenue is relative though. For the developer, if it makes $500k over the product's lifetime, it can be worthwhile. For Facebook, if it only makes $500k, it's a waste of resources.
Maybe, but working hard for months/years a chance at a job offer doesn't sound that amazing anyway.
BTW I worked in a startup once and a guy, who was developing opensource plugin for our product, applied for a job with us. The owner (a known blogger BTW) said "Why hire him if he's already working for us?"
I think that was the owner being shortsighted. If the plugin was something that a reasonable fraction of your users would like to have, then very shortsighted.
Not only you had a person that already knew much more about your product than the average potential hire, but a person that probably was interested in your product (and maybe knew what users wanted) too.
Pretty much the only way to win it so make something that provides marginal revenue, which makes reimplementation not worth it for the giant (but potentially worth it for you). I suspect a lot of Unity and Unreal plugins and authoring tools reside in that niche.