I spent a weekend reading all 540 comments from Hacker News' biggest Ask HN on professional development: "What is the best money you have spent on professional development?" (524 points, 540 comments). The results surprised me — and they might change where you put your next learning budget. The ranking (by how many DISTINCT commenters named it) # Resource Mentions Est. price 1 Therapy / coaching 51 ~$100/mo 2 Writing / blogging practice ...