One of the greatest software engineers of all time, Ken Thompson, recently shared the story behind the creation and design of the Go programming language. Today, Go is one of the most beloved, widely-used, and respected languages in the industry. This article delves into Thompson’s time at Google, where he, as a lead engineer, co-developed Go after joining the company in 2006.
A Pioneer of Computer Science
For those unfamiliar with his work, Ken Thompson is an American pioneer of computer science. His career, largely spent at Bell Labs, is legendary. He designed and implemented the original Unix operating system and invented the B programming language, the direct predecessor to C. Thompson was also a key creator of the Plan 9 operating system.
His other notable contributions include foundational work on regular expressions, the early text editors QED and ED, the definition of the UTF-8 encoding system, and pioneering work in computer chess, including the creation of endgame table bases and the chess machine “Belle.” When you talk about the titans of engineering, Ken Thompson’s name is always at the top of the list.
The C++ Problem at Google
The story of Go begins with a talk at Google. A company representative for the ANSI C++ standards committee had just returned from a meeting and was describing the language’s new features.
“The new stuff, in my opinion, was bigger than the language,” Thompson recalled. This philosophy—that features shouldn’t overshadow the core language—seems to be a lost art, especially in modern frameworks. Often, a great tool is introduced, only to become bloated with “improvements” that obscure its original purpose. Frameworks like React and Next.js, and even Go to some extent, have evolved so much that they feel like entirely new languages.
Thompson found the C++ additions bewildering. “I didn’t understand most of it,” he admitted. “It was forms of pointers that meant some other thing besides pointer… it had notions on the data or something.” The hour-long talk was dense, covering just the so-called improvements to C++.
The Breaking Point: Compilation Hell
Around the same time, Thompson’s colleagues, Robert Griesemer and Rob Pike—the other co-creators of Go—were complaining about a massive problem within Google’s monolithic repository.
At Google, all source code lived in a single repository. This meant you could reference any library from any piece of code. The consequence? A simple ten-line program could trigger a five-million-line compilation.
It was messy. Worse, the simplest libraries would be loaded and examined hundreds of thousands of times, resulting in gigabytes of code being processed for every single compilation. While caching mechanisms were implemented to avoid re-examining previously seen code, the problem persisted. The sheer scale was staggering. Google had dedicated hundreds of CPUs in its data centers just to handle compilations for its engineers.
Even with this immense power, things only got worse. “You’d wait 15 minutes with a 100 computers compiling a 10-line program,” Thompson explained.
This was in the early 2000s, around 2006 or 2007, when Google was the epicenter of software innovation, attracting brilliant minds from Bell Labs and beyond. They were pushing the envelope, but this compilation bottleneck was crippling their iteration speed. Every minor change required a monumental effort to compile, hurting productivity and frustrating developers.
The Birth of a New Language
Rob Pike, in particular, was deeply troubled by the system’s overwhelming complexity. The frustration reached a boiling point.
“The three of us got in an office and said, ‘What are we going to do about it?’” Thompson recounted. His solution was audacious and direct: “I said, ‘Let’s write a language.’”
In that moment, three of the world’s top engineers decided to solve a company-wide infrastructure problem by creating a new programming language from scratch. It was a bold, decisive move. “So, we wrote a language. They don’t make them like this anymore,” he said.
The team was a perfect combination of talent. Rob Pike understood the deep-seated software problems at Google. Ken Thompson brought his extensive history with language design and compilation. Robert Griesemer was a “jack of all languages,” possessing a theoretical mastery of programming language mechanics. Thompson focused on the hard parts—compilation, garbage collection—while the others brought their unique expertise. It was a dream team.
The Power of the Standard Library
The initial version of Go was barebones, much like C, with no batteries included. However, after the original creators laid the foundation, other brilliant engineers and open-source contributors stepped in to build out what would become one of Go’s greatest strengths: its standard library.
This library is now famous for its comprehensive and magnificent design. It provides robust, production-ready packages for everything from networking and cryptography to text processing and concurrency. There are very few reasons to look outside the standard library for common tasks. While you certainly can use third-party packages, the reality is that almost everything you need is already built into the language.
“Now I write in Go almost exclusively,” Thompson noted, “and almost exclusively I use nothing but the standard libraries.”
Simplicity and Speed
One of Go’s defining features is its simplicity. It is arguably one of the easiest modern languages to learn, perhaps rivaled only by Python in its accessibility. You can grasp the fundamentals in an hour.
The learning experience is often interactive. Many online Go tutorials feature a terminal-like window where you can type code and see it execute instantly. As you type, the program runs and provides the answer, creating a tight feedback loop that accelerates learning.
package main
import "fmt"
// A simple function to illustrate Go's syntax.
func getGreeting(name string) string {
// Returns a personalized greeting.
return fmt.Sprintf("Hello, %s! Welcome to Go.", name)
}
func main() {
// A simple 10-line program can be powerful in Go.
// This demonstrates the ease of use.
users := []string{"Alice", "Bob", "Charlie"}
for _, user := range users {
message := getGreeting(user)
fmt.Println(message)
}
}
The story of Go is a fascinating look into the minds of brilliant engineers. It evolved from a practical solution to a real-world problem at Google, and through collaboration, it became a powerful, accessible language for the entire world. It stands as a testament to the idea that sometimes, the best way to fix a complex problem is to start over with a simple, elegant solution.