Based on my experience with Bun recently, I really have a lot to say. Although I am just an ordinary developer, I feel it is necessary to express my views regarding Bun's future development.
I scrolled through Bun's official X account as well as the author's personal X account, and I found that even after being acquired by Anthropic, most of the official marketing is still obsessed with the "performance" narrative, namely, repeatedly emphasizing how much processing time a new feature cuts down compared to competitors or older features.
Then there are the new features.
Regarding the new features, the ones that left a deep impression on me are native support for Markdown and Stage 3 Decorators.
Stage 3 Decorators are certainly a great feature, but as for Markdown, I truly cannot understand: is rendering Markdown really the proper job of a JavaScript Runtime?
From what I knew about Bun previously, it can do almost anything, from a bundler to built-in database support — I could understand those previous features as Bun's "All-in-One" strategy. But I really cannot understand the Markdown support. I feel this is no longer "All-in-One"; this is "All-in-Everything." Doing this will truly cause maintenance costs to skyrocket.
Granted, Bun is now under Anthropic (acquired in December 2025), and Anthropic has a lot of money, but no amount of money can allow a team to add features limitlessly while also guaranteeing quality. That is extremely difficult.
Speaking of quality. I have expressed similar views in the comment sections of some issues(Issue 26660 and Issue 26625) before, but I assumed my views wouldn't get enough attention, which is why I opened this issue.
I think it was around 2023 when I first learned about Bun. At that time, star number and open issues weren't that high. Back then, I thought Bun was pretty good; although there were some minor bugs, it was generally acceptable.
But now, in March 2026, although Bun's star count has reached nearing 100k, the number of open issues has also hit a staggering 4.9k (Now it has dropped to 4.8k again and is now stably maintained at this level long-term) , and this is even with a bot automatically closing duplicate issues.
JavaScriptCore comes from Apple, and getting it to run on Windows indeed requires some adaptation work. I am also aware that in production environments, Bun mostly runs on GNU/Linux (especially backend web apps). From this perspective, it's understandable that Bun focuses more on POSIX-compliant operating systems like macOS and GNU/Linux — but right now, many developer-side tools like Claude Code and OpenCode are also based on Bun. Objectively speaking, the percentage of users running these tools on Windows is not trivial. You can't just abandon one group of users to cater to another, right? Moreover, even though I have now switched to macOS, I see many users in the issues reporting that Segmentation Faults also exist on macOS and GNU/Linux. This shows that the instability is not just limited to Windows compatibility issues.
Some time ago, I submitted an issue about a Segmentation Fault related to OpenCode. At that time, I was still using Windows 11 as my development environment. The AI @robobun very quickly called Claude Code and submitted a PR. I downloaded that PR to check it and found it didn't solve my problem, and I explicitly replied back then saying it didn't solve it. But unfortunately, this PR was still merged by the author. I opened another issue and did not get a meaningful response.
"Vibe coding" --- everyone is discussing this term, and sure, you can also have "Vibe Debugging."
But what is Bun? Bun is a runtime, it is an infrastructure! If it's a little demo, or a relatively unimportant app, I think handing it over entirely to AI for fixing is fine. But for the incident I mentioned above, can you really do that? AI is very important to Bun and to Anthropic, and I can understand Anthropic wanting to use @robobun as a window to demonstrate Claude AI's capabilities. But why merge this PR without conducting a rigorous PR Review? Isn't this just using AI-generated hallucinations to cover up Bun's quality issues?
Bun is long past being a seed-round project, Bun is now used by commercial products, and Claude Code's capabilities are built on it. I think this level of stability is hardly reassuring, nor can it bear the weight of an enterprise-grade production environment.
I strongly urge the Bun team to take the issue of stability seriously. To this end, I hope Bun can be like Microsoft: Since January of this year, Windows 11 has experienced a large number of stability issues, and Windows 11 has similarly added some flashy but impractical features. However, we see that Microsoft has committed to listening to users' voices in the coming months and focusing their efforts on fixing Windows 11's stability issues. I hope the Bun team can make a similar commitment and focus their energy on fixing Bun's stability issues.