A mechanical engineer transitioned to software development over 3.5 years, starting with freelance web development while self-teaching through online courses. After initial job rejections, he built a portfolio, practiced 350+ LeetCode problems, and optimized his LinkedIn profile to attract recruiters. This approach led to multiple offers including PayPal and Amazon, ultimately landing a Software Engineer 3 role at Google with a 70% salary increase. Key success factors included persistent learning, building real projects, mastering data structures and algorithms, and strategic profile marketing rather than direct applications.