A discussion on Hacker News explores the challenges of writing constant-time cryptographic code in high-level languages like JavaScript. The thread centers on a blog post by "some_furry," which highlights how the V8 JavaScript engine’s optimizations can inadvertently undermine constant-time implementations, leaking secret data through timing side channels. Participants debate the feasibility of achieving true constant-time performance in managed runtimes. One user argues that side-channel attacks inherently defeat high-level abstractions, making "whack-a-mole" fixes unsustainable. Others suggest that while achieving perfect security is difficult, developers can mitigate risks by using algorithms without secret-dependent timing, or by compiling Rust to WebAssembly to exert more control over the generated assembly. The core tension remains: cryptographic software often relies on performance guarantees that engines like V8 never explicitly promised. While experts recommend avoiding high-level languages for sensitive tasks like dTLS, others note that the path forward involves rigorous verification of the underlying machine code and clearly defined threat models. Ultimately, the discussion emphasizes the mismatch between the requirements of secure cryptography and the optimization-heavy nature of modern web runtimes.