I retired in 2018 after 34 years in the defense industry as a software engineer and manager. Since then I have been a math, physics, and computer science tutor for high school and college students. I have a background in both math and computer science - I was a math/computer science major at Dartmouth College and I have a master's degree in computer science from Purdue University. I worked on many math-intensive applications as a software engineer. I have over 5000 hours experience in online tutoring on different platforms. My computer science tutoring experience includes computer programming (C++/C/Java/Python) as well as data structures, algorithms, operating systems, and theory of computation. My tutoring approach is that I look for gaps in a student's understanding. Then we focus on plugging those gaps. I believe that even the most complex topics can be broken down into key concepts which can then be mastered. Mastering key concepts leads to student confidence and the ability to do well in a subject.