https://www.codementor.io/ https://www.codementor.io/ sort of fits your requirements. But behavioral economics says: > Sometimes asking someone to do somethin

https://www.codementor.io/ https://www.codementor.io/ sort of fits your requirements. But behavioral economics says: > Sometimes asking someone to do something for nothing is more powerful than paying them. [1] Also, StackOverflow incurs zero monetary cost. There is a stark difference in people's behavior towards zero cost, even if the price difference is only 1 cent. [2][3] [1]: https://danariely.com/why-bankers-would-rather-work-for-000-than-500k/ https://danariely.com/why-bankers-would-rather-work-for-000-... [2]: https://web.mit.edu/ariely/www/MIT/Papers/zero.pdf https://web.mit.edu/ariely/www/MIT/Papers/zero.pdf [3]: https://youtu.be/WS1bwMdgmKc https://youtu.be/WS1bwMdgmKc