Getting initial traction and customers is definitely the hardest in my experience. Refining the product, marketing, and achieving product-market fit takes a lot of iterations before you get it right. Just gotta keep at it and not get discouraged!
Maybe the early scaling phase. Balancing the need for quick expansion with maintaining product quality, culture, and managing limited resources can be incredibly challenging.
I’ve found the product development stage to be the most challenging. Balancing feature requests, bugs, and user feedback while trying to meet deadlines can be overwhelming.