Bill Gates’s first real job was as a systems programmer at TRW Systems Group, where he worked from January to September 1973, while still in high school. He was 17 years old, and his duties involved file design and modifications to the company’s operating system. But the path to that job started years earlier, with a series of coding projects that gave Gates professional-level experience before he ever drew a paycheck.
Programming at Lakeside School
Gates first got his hands on a computer at Lakeside School, a private school in Seattle, in the late 1960s. The school had purchased access to a timesharing terminal, which was rare for any school at the time. Gates threw himself into programming, teaching other students about computers and building practical tools for the school itself. One notable project was digitizing the school’s class scheduling system. He even figured out how to hack that system to place himself in classes with more girls. The school could have hired an outside computer expert for the scheduling work, but Gates and his classmates had already proven they could handle it.
These weren’t just hobby projects. Gates was solving real problems with real users, building the kind of hands-on experience that most people didn’t encounter until well into a professional career. It also introduced him to Paul Allen, a fellow Lakeside student who shared his obsession with programming and would eventually co-found Microsoft with him.
The TRW Systems Group Job
In January 1973, Gates landed a position at TRW Systems Group, a major defense and technology contractor. His title was systems programmer, and his work focused on file design and modifications to the operating system. This was serious, professional software engineering, not student busywork. He held the position for about nine months, through September 1973.
Gates later listed this job on his resume when he enrolled at Harvard in 1974. For a college freshman, having nine months of systems programming at a company like TRW was unusual. The experience gave him confidence that he could compete with professional engineers and reinforced his belief that software was where the future was heading.
Traf-O-Data: A Business Before Microsoft
Around the same time, Gates and Paul Allen launched their own venture called Traf-O-Data. The startup built a computer system designed to count traffic for local governments, processing the data from rubber tubes stretched across roads. It was a legitimate attempt at a real business, not just a science fair project.
Traf-O-Data ultimately failed. Just as the company started gaining traction, states began offering their own traffic-counting services to local governments for free. The business model evaporated almost overnight. Gates and Allen later acknowledged the venture was a commercial failure, but the experience of building a product, finding customers, and running a small operation together proved invaluable. Many of the working habits and the partnership dynamic they developed during Traf-O-Data carried directly into Microsoft, which they founded in 1975.
Why It Mattered
By the time Gates dropped out of Harvard to start Microsoft, he had already spent roughly six years writing real code for real organizations. He had worked inside a large technology company, built and shipped a commercial product, and managed a small business. Most 19-year-olds in 1975 had none of that experience. Gates wasn’t just a talented programmer who got lucky. He had logged thousands of hours of practice and professional work before making the bet that personal computing would change the world.