Citing a few accomplishments, unsure whether one would call them 10X or not. You decide. :-)

Year 2000. I was a masters student helping a professor's research group. They wanted a complex GUI app for Augmented Reality built using a computer vision library developed by someone else. I was ambiguously described the requirements verbally. I conceptualized the UI/UX, wrote 30K lines of code in C++ for the Windows App, tested everything and showcased to them, all done in about a month. The user experience exceeded their expectations. Practically no bugs ever found. They were impressed and I received research assistant position under them.

Year 2007. I made a proposal that received mostly skepticism on feasibility. One manager supported but could not allocate resources. Later, two managers, both secretly, had two-month interns work on the same, as I discovered during the intern seminars! One 4-5 years experienced person also separately worked on the same. The intern projects worked but did not meet the accuracy needed. The experienced coworker's system worked better, though still did not achieved the performance. That system was taking 40 minutes for one run, and they were reaching out for ways to optimize. Soon, a high-severity issue happened which required the proposed system with high accuracy, and I was in the line of fire. Worked heavily for two days. Came up with a simple idea on how to solve it. Coded.
Problem solved. Had ~15 times higher accuracy. Had real-time processing. I summarized the delivered system's capabilities in an email to a large audience. Those unaware thought it was conclusion of a few month long project. After having learnt that I had done it in two days, someone stopped by my office and said, "I would rather kick my butt than sit in a programming competition with you". The system saw good adoption and continued usage for years without any issues. One single bug discovered over its lifetime, which happened because the code had made an tacit assumption that was invalidated by later devices under test.

2010-11. A group was working on a complex problem for video half-toning. One person had 25 years of experience in image processing and color science. An intern who was pursuing research in the same area was hired to solve the problem under the guidance of the noted expert. I pointed to the intern that he's taking a complicated route to solving without having ruled out a potentially simpler path. He agreed but did not do anything. Two months internship over. Later, the problem came to me as I needed to solve the same for a different type of display system. I thought about it, prototyped, and showed an unambiguously better solution in two days net, applicable to previous system as well. One of the previous owners of the problem happily congratulated me. Resulted in filing of a patent application.

I can cite many more examples.

I had earned #2 spot at university programming competition.

I used to be writing about 600-800 lines of code per work day, with defect density of less than 0.5 bug per thousand lines of code. There have also been times working on difficult research problems when I've been as slow as 200 lines of code in an entire month.

I am no longer all that because of some unfortunate circumstances. I am not actively coding and tend to make more mistakes these days though still am considered exemplary in whatever I produce.