Simon Willison

Feeling sad about AI

Simon Willison reflects on the emotional impact of AI tools that can produce code quickly, noting that many developers experience an initial sense of disheartenment. He argues that recognizing the shift from coding to higher‑level problem solving allows experienced engineers to leverage new tools and add greater value. Willison emphasizes that software engineering has always faced rapid change, so adapting to AI is part of the profession’s ongoing evolution.

Simon Willison
Aug 26

Quoting Paul Dix

The article highlights Paul Dix’s astonishment that AI was able to generate one million lines of code and then refine it over several months into a reliable software product now used by millions of developers. Dix argues that this achievement is far more impressive than merely translating code between languages, emphasizing that with a verification system and clear guidance, AI can produce and iteratively improve highly complex, sophisticated software until it functions perfectly.

Simon Willison
Sep 12

Quoting Paul Ford

Simon Willison reflects on the evolving role of software developers in the age of AI, noting that while AI can produce high‑quality code, it also enables poor execution that leads to project failures. He argues that the industry is beginning to recognize the continued need for human collaboration and expertise to truly innovate. The piece highlights the tension between automation and the essential human element in software creation.

Simon Willison
6d ago

Claude Cowork and chat are now one Claude

Claude Cowork and the standard chat interface are merging into a single Claude experience, allowing users to hand over tasks or ask quick questions that the system will continue to handle even after the laptop is closed. The rollout will begin with Pro and Max plan users across web, desktop, and mobile, and will extend to new users on these plans over the coming weeks. This integration suggests Claude is evolving into a general agent, simplifying the distinction between Cowork and regular Claude usage.

Simon Willison
Sep 14

What blog posts influenced your thinking the most?

Simon Willison reflects on three blog posts that shaped his professional outlook: Joel Spolsky’s *The Law of Leaky Abstractions*, Will Larson’s 2018 article *Migrations: the sole scalable fix to tech debt*, and Charity Majors’ *The Engineer/Manager Pendulum*. Each piece offered a distinct lesson—recognizing hidden complexities in abstractions, embracing migrations as a core engineering skill, and validating the fluid movement between engineering and management roles. These insights collectively encouraged Willison to deepen his technical understanding, prioritize migration work, and feel empowered to shift career tracks without fear.

Simon Willison
Aug 22

More than just code review

The article discusses the essential skill of effectively instructing coding agents and verifying their changes. It highlights that while line‑by‑line code review is one method, it is not the most efficient way to validate software changes. The focus is on confidently guiding agents and confirming correct implementation without exhaustive inspection.

Simon Willison
Aug 28

Just a rumour of a bug is enough to find a security exploit these days

The article reports that rumors of bugs in open‑source projects now trigger rapid security exploits, with automated agents probing for vulnerabilities within minutes of a patch being discussed. Anil Madhavapeddy demonstrates how modern coding agents can exploit even minimal hints, and rclone maintainer Nick Craig‑Wood notes a dramatic spike in security disclosures and delayed CVE assignments. The post highlights the need for new processes to protect open‑source communities from swift exploitation.

Simon Willison
Sep 14

Quoting Laurie Voss

Laurie Voss argues that while the cost of writing code has fallen dramatically, the costs of reviewing, fixing, and operating software are rising and will continue to do so. She emphasizes that the true expense lies in understanding user needs, precisely defining requirements, and ensuring a pleasant user experience—costs that are unique to each software product and do not scale with reuse. As software demand grows without an upper limit, these user‑centric costs will dominate the overall development effort.

Simon Willison
Sep 6

There's No Limit to How Bad Code Can Get

Simon Willison discusses the pitfalls of attempting to replace a legacy system with a new one when technical debt is overwhelming. He explains that while the old system continues to evolve, developers lack incentive to improve it, and the new team, initially fast, eventually struggles to understand and deliver the required functionality. The result is often two partially functional systems in production, with the new one abandoned and the old one still running, increasing risk and complexity.