Why Do Companies Stop Using Haskell? | Vaibhav Sagar | ZuriHac 2026

Vaibhav Sagar examines the business, organizational, and technical forces that lead companies to abandon Haskell despite the language's technical success.

Why do companies stop using Haskell, even when the language itself works well? Vaibhav Sagar examines real-world cases to uncover the business, organizational, and technical forces that can push companies away from Haskell. The talk begins by examining Haskell's unique position in the software industry. While Haskell has proven itself capable of supporting successful businesses, it remains neither a mainstream technology nor the industry's newest trend. This creates a situation where failures are often attributed to the language itself, even when broader business forces are responsible. Sagar contrasts characteristics of the Haskell ecosystem with common business priorities such as profit maximization, short-term incentives, and the systematic undervaluation of maintenance work. Through a series of recurring patterns, he analyzes how Haskell projects can end. These include large-scale rewrites, second-system effects, failed experiments, vanity projects, funding challenges, acquisitions, leadership changes, technology-fashion cycles, overly complex codebases, and infrastructure limitations. Along the way, he connects these stories to broader software engineering concepts such as technical debt, process improvement, organizational incentives, and long-term maintainability. Rather than presenting these outcomes as uniquely Haskell-specific, the talk argues that many of the same dynamics affect other niche programming languages. Sagar offers practical advice for engineers, emphasizing professional reputation, understanding organizational incentives, investing political capital carefully, contributing to open source, and recognizing when it is time to move on. The talk concludes with a personal reflection on the opportunities, community, friendships, and career experiences that Haskell has enabled, arguing that even when individual companies stop using Haskell, the broader functional programming ecosystem continues to grow and create value. Chapters 00:00:00 Introduction And Motivation 00:05:02 Haskell's Position In The Software Industry 00:07:43 How Companies Make Technology Decisions 00:12:15 Why Companies Choose Haskell 00:14:16 Rewrites And The Second System Effect 00:21:16 Experiments, Funding, And Failure 00:22:00 Vanity Projects And Technology Choices 00:23:25 Consulting, Clients, And Sustainability 00:24:34 Acquisitions And Team Transitions 00:26:04 Leadership Changes And Political Capital 00:27:05 Trend Chasing And The Magpie Effect 00:28:45 Complexity And Maintainable Haskell 00:30:17 Scaling Challenges And Ecosystem Investment 00:33:21 Career Strategy And Professional Leverage 00:35:14 Unionization, Community, And Long-Term Thinking 00:37:03 Why Haskell Is Still Worth It 00:39:31 Audience Questions And Discussion About the Speaker Vaibhav is a Haskell and Nix developer and uncompetitive powerlifter. He is the current maintainer of IHaskell, which allows you to use Haskell inside Jupyter notebooks. Vaibhav Sagar prese