Quoting Mitchell Hashimoto

2026-05-14 · Source: Simon Willison's Weblog · Field: Technology & Digital — Software Development & Engineering · Depth: Intermediate, quick

Summary

Mitchell Hashimoto observed on May 14, 2026, that programming languages are becoming increasingly fungible, contrasting with their historical role as a "lock-in" factor. He cited the Bun project's ability to rewrite its codebase from Zig to Rust in approximately one to two weeks as evidence. Hashimoto suggested this demonstrates that even languages like Rust, while currently useful, are ultimately expendable, as projects can rapidly switch to alternatives if needed. This flexibility indicates a significant shift in the perceived permanence and strategic importance of specific programming language choices for software development.

Key takeaway

For engineering leaders evaluating technology stacks, recognize that your choice of programming language no longer represents a long-term lock-in. Your teams should prioritize development velocity and project requirements over perceived language permanence, as demonstrated by Bun's rapid Zig-to-Rust port. Be prepared to pivot languages quickly if a better fit emerges, reducing future technical debt and increasing agility.

Key insights

Programming languages are increasingly fungible, reducing vendor lock-in and making specific languages expendable.

Principles

• Language choice is less permanent.
• Rapid language migration is feasible.

In practice

• Evaluate language alternatives frequently.
• Prioritize project needs over language loyalty.

Topics

• Programming Language Fungibility
• Developer Agility
• Bun Project
• Rust Programming
• Zig Programming

Best for: VP of Engineering/Data, Software Engineer, Director of AI/ML, CTO

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Editorial summary, takeaway, and curation by AIssential. Original article published by Simon Willison's Weblog.