Simon Willison Shares Three Essays That Shaped His Career

In a recent industry reflection, prominent software engineer and open-source developer Simon Willison shared the three external blog posts that have most profoundly influenced his professional mindset. Published on September 14, 2026, Willison's list highlights foundational concepts in software design, technical debt management, and career progression, providing a roadmap for practitioners looking to navigate the complexities of modern software development.

The first influential piece Willison highlighted is Joel Spolsky's classic essay, "The Law of Leaky Abstractions." Reading this early in his career, Willison noted that it instilled a lifelong habit of investigating the underlying layers of his technology stack to prepare for when those abstractions inevitably fail.

The second recommendation is a 2018 post by Will Larson titled "Migrations: the sole scalable fix to tech debt." Larson argues that migrating systems—such as swapping databases or replacing services—is a core engineering skill to be mastered and repeated, rather than an avoided one-off chore. Willison praised this perspective for framing migrations as an essential part of healthy software maintenance.

Finally, Willison credited Charity Majors' essay, "The Engineer/Manager Pendulum," with reshaping his view of career progression. The piece helped him overcome anxieties about transitioning from engineering management back to an individual contributor role. Majors argues that swinging between these two tracks throughout a career is common among successful developers and ultimately enhances performance on both sides.

For modern software practitioners, Willison's curated list serves as a reminder of the enduring value of foundational engineering principles. In an era increasingly dominated by rapid AI development and shifting organizational structures, mastering underlying abstractions, treating system migrations as routine skills, and embracing non-linear career paths remain critical strategies for long-term professional growth.