The Invisible Glitch: Dan Luu on the Phenomenon of 'Bug Blindness'

Software engineer Dan Luu argues that a vast number of computer users, including some developers, suffer from "bug blindness." This psychological state occurs when individuals encounter software defects frequently but fail to recognize them as errors, instead accepting them as normal behavior.

Luu reports observing hundreds to thousands of bugs per week during his own daily computer usage. He notes that the issue is often not that bugs are rare, but that people hit the same errors repeatedly without noticing them. This gap in perception is so significant that Luu has been hired by directors, VPs, and executives specifically to evaluate products because of his ability to detect defects that others routinely miss.

The Baseline of Brokenness

This concept is part of a larger critique by Luu regarding the systemic lack of quality in the modern software industry. By documenting a "week of bugs," Luu has highlighted the sheer volume of failures present in common operating systems and applications. He suggests that the industry's failure to prioritize rigorous testing has created a baseline of brokenness. Because so many users are blind to these failures, software is perceived as functional even when it is objectively flawed.

Why Perception Matters

The implications of bug blindness extend beyond individual frustration to market dynamics. If a significant portion of the workforce and the general user base cannot identify software defects, there is very little internal or market pressure for companies to fix them. When broken behavior becomes the expected norm, the incentive to invest in quality assurance diminishes, further entrenching the cycle of low-quality releases.

For professional programmers, Luu argues that overcoming this blindness is a critical skill. The ability to see a glitch for what it is—an error rather than a quirk—is essential for improving QA processes and delivering more reliable products. Without this awareness, developers cannot effectively address the root causes of software instability.

Training the Eye

Luu posits that this blindness is not a permanent condition. He suggests that people who are inclined to notice bugs can be "cured" of the condition simply by having specific bugs pointed out to them over the course of a few weeks. By training the eye to recognize errors, Luu believes developers and users alike can shift their perception of software quality and demand higher standards from the tools they rely on daily.