I believe no technical problem is too big or too small if it makes an impact on the lives or business of others. I'm something of a bug exterminator and find a lot of enjoyment in fixing things, almost as much joy as I find in building fast MVP's for real-world problems.
For the past 8 years, I've shaped and built production-scale apps on web and mobile for early-to-mid stage startups, 3 of which went through YC and were well-funded. I've worked on engineering teams at companies as big as Uber and Salesforce, and as small Spiceworks (~300), Umbel (~30), SparkCognition (~12), and TrustedFor (3), myself being the first employee. I also worked as a Product Manager for Gigster in its first year taking over 50 projects to successful completion before starting my own agency.
Shipped new AI Detect product, wrote all the web-side code for it. Product is a canvas-based platform, so tons of geometry and math. Raised effeciency, moved computations to web worker, or separate thread on express server. Took a lot of ownership over the UI, polish, responsiveness, etc.