Migrating from Go to Rust

amusingimpala75

This is probably going to sound generic / repetitive, but my biggest complaint about Rust is the package management situation, which is entirely the result of the developer mindset. I love the ergonomics on the rust side (the functional approach to data types is beautiful), but I’m working on two projects side by side, one in rust and one in go at the moment. The dependency trees are entirely different beasts, with most of the stuff on the go project covered by the stdlib whereas I think the rust project is over 400 despite asking for just rusqlite (sqlite), clap (cli), ratatui (tui), and tauri (gui), the last of which is by far the worst offender but even without it, it’s still close on 100 which is crazy. If there were (and maybe there are, I just haven’t found them) decently maintained alternatives to the rust crates that actually have a sane dependency approach , I’d feel much better. I’m just trying to not shai hulud my system, and the rust-web people seem to want to turn cargo into npm in that regard.

gertlabs

I liked Rust before running a benchmark, but the gap between how effectively most LLMs write in Rust vs Go was still surprisingly large to me (especially in agentic harnesses where they can fix the initial environment issues). I've become a pretty big Rust evangelist after seeing that. We've had a lot of success writing batch processing tools in Rust to be called by our existing codebase, but haven't attempted a full production migration... yet. I will say that many of the issues with Go in the article, especially re: nil handling are increasingly solved by thorough coding reviews with Codex. Better to not have the issue in the first place, sure, but these kinds of security bugs are becoming optional to developers who put in at least as much effort to review and understand code as they put into the initial design and execution. Language data at https://gertlabs.com/rankings?mode=agentic_coding

arccy

perhaps the oncall is better if you write your own services, but as an SRE / ops person who has to run other people's services, rust ones just generally seem to be worse: logs that are so verbose but seem to tell you nothing, statsd seems to be the only choice for metrics, contextless errors everywhere, memory "leaks" (more like runaway memory use) that the developers swear are impossible because it's rust, overall just less mature across services written by both in house and oss teams

Animats

I could see migrating from C or C++ or Python to Rust, for various reasons, but for web back-end work Go is a good match. I write almost entirely in Rust, but the last time I had to do something web server side in Rust, I now wish I'd used Go. The OP points out the wordyness of Go's error syntax. That's a good point. Rust started with the same problem, and added the "?" syntax, which just does a return with an error value on errors. Most Go error handling is exactly that, written out. Rust lacks a uniform error type. Rust has three main error systems (io::Error, thiserror, and anyhow), which is a pain when you have to pass them upward through a chain of calls. (There are a number of things which tend to be left out of new languages and are a pain to retrofit, because there will be nearly identical but incompatible versions. Constant types. Boolean types. Error types. Multidimensional array types. Vector and matrix types of size 2, 3, and 4 with their usual operations. If those are not standardized early, programs will spend much time fussing with multiple representations of the same thing. Except for error handling, these issues do not affect web dev much, but they are a huge pain for numerical work, graphics, and modeling, where standard operations are applied to arrays of numbers.) Go has two main advantages for web services. First, goroutines, as the OP points out. Second, libraries, which the OP doesn't mention much. Go has libraries for most of the things a web service might need, and they are the ones Google uses internally. So they've survived in very heavily used environments. Even the obscure cases are heavily used. This is not true of Rust's crates, which are less mature and often don't have formal QA support.

amazingamazing

Rust is great. However in an agentic world go will win. Look no further than incremental build times. This, combined with high token costs mean that for a given application it simply will cost more to to write it in Rust than Go. This can easily be justified for many usecases, but for your vanilla crud app, do you really need Rust? Per the article, you are getting 20-50% better more performance with Rust. Not worth it unless your team was already fluent in Rust. Now consider a scenario where your team uses AI exclusively to code, now you are spending more time and tokens waiting around to consume large rust builds. As far as I know this is an inherent property of Rust to have its safety guarantees. I think Rust makes sense for a lot of cases, but for a small web service, overkill and unnecessary imho. If someone ported their crud app from Go to Rust I would question their priorities. Again I am speaking more in terms of software engineering economics than anything else. Yes, I know in a perfect world Rust binaries are smaller, performance is better and code more “correct”, but the world is hardly perfect. People have to push code quickly, iterate quickly. Teams have churn, Rust, frankly is alien for many, etc.

Thaxll

"services that your organization relies on, that have high uptime requirements, that are critical to your business" Kind of funny when your Rust service runs on Kubernetes.

kayo_20211030

If you have a green field, by all means write it in rust. If you have a brown field, and a functional profitable system, rewrite the parts that need rewriting in the original language, whatever that is, and carry on. Make your systems better in small measurable ways, with the language you know and a team you trust to implement it all. Anything else is a wasteful religious argument.

arjie

I do like using Rust quite a bit, but the presence of arbitrary build-time code in build.rs is very risky until we get better at implementing dev-time sandboxing.

geenat

If verbosity is a main stickler, this is coming to golang 1.28 which will cut it down drastically: https://github.com/golang/go/issues/12854#issue-110104883

nemo1618

LLM writing tells are getting more subtle, but they still jump off the page for me, in particular the word "genuine:" "This is the area where Go genuinely shines, and it’s worth being precise about why" "the lack of GC pauses is a genuine selling point" "Humans are genuinely bad at reasoning about memory" "There are cases where the borrow checker is genuinely too strict" tbc I don't think the article was fully AI-generated, just AI-assisted. If so, the author did a genuinely good job of it! No one else is commenting on it, so clearly it didn't detract much from the substance. It's just weird that this is becoming increasingly common, and increasingly hard to detect.

0xfurai

The "when to enforce it" framing is what sticks with me. Go and Rust agree on safety, concurrency, simple deployment, but Go says "catch it in review" and Rust says "catch it before it compiles." The right answer depends entirely on how expensive a production incident is for you vs. how expensive slower iteration is.

amelius

Go has shorter and more predictable GC pauses. If a reference count drops to zero in Rust, it may take an unbounded time to free all the things it refers to (recursively if necessary).

cbondurant

I already use Rust and don't have experience with Go, so this article maybe isn't super for me. I do have one nitpick though: Stating that data races are "caught at compile time" in Rust feels like it is overstating the case, at least a little. It sounds a bit like its implying Rust can also handle things like mutual lock starvation, or other concurrency issues. When that's simply not the case. I know "data race" is technically a formal term, with a decently narrow scope, yet I still think it could be a bit clearer about it.

tptacek

This is a weird document that is simultaneously trying to serve as a migration guide and an advocacy document for Rust. Ultimately, if you have to ask , the Rust vs. Go consideration boils down almost completely to "do you want a managed runtime or not". A generation of Rust programmers has convinced itself that "managed runtime" is bad, that not having one is an important feature. But that's obviously false: there are more programming domains where you want a managed runtime than ones where you don't. That's not an argument for defaulting to Go in all those cases! There are plenty of subjective reasons to prefer Rust. I miss `match` when I write Go (I do not miss tokio and async Rust, though). They're both perfectly legitimate choices in virtually any case where you don't have to distort the problem space to fit them in (ie: trying to write a Go LKM would be a weird move). The Rust vs. Go slapfight is a weird and cringe backwater of our field. Huge portions of the industry are happily building entire systems in Python or Node, and smirking at the weirdos arguing over which statically typed compiled language to use. Python vs. (Rust|Go) is a real question. Rust vs. Go isn't.

wpollock

Very nice write up! I am a fan of Rust and have little exposure to Go. That said, a couple of very minor points: cargo audit is not built-in, it is 3rd party. (The comparison table near the top isn't clear about that, and the following text stating more is built-in for Rust than for Go might be confusing. I would suggest adding an asterisk to mark built-ins in that table.) cargo watch has been in "maintenance mode" for some time. The author of that suggests cargo bacon instead.

hasyimibhar

It is also easier to make your code deterministic with Rust vs with Go, which is incredibly useful if you need to perform deterministic simulation testing + property-based testing. I recently wrote a Postgres-to-Iceberg data mirroring tool [1] in Go, but I ported it to Rust because I wanted the ability perform DST without fighting Go's runtime [2]. But if the domain is not critical that warrants DST, I would still pick Go over Rust any day. [1] https://github.com/polynya-dev/pg2iceberg [2] https://www.polarsignals.com/blog/posts/2024/05/28/mostly-ds...

LoganDark

I still think rustfmt made a mistake by going with four spaces. It's basically inferior for everything except forcing everyone to use the same indentation width, which is actually a downside, since I constantly encounter two-space indent codebases that I can't read and also can't change to four spaces because it's not tabs. Also translating spaces to tabs visually is undecidable thanks to alignment, while the inverse is not true. Ugh.

dilyevsky

> Under heavy allocation, P99 latency tails are noticeably worse than a Rust equivalent that simply doesn’t allocate on the hot path. Lmao so not an equivalent then? Standard glibc malloc, which is default in rust, will also similarly degrade albeit for different reasons.

h4kunamata

Read migrating from one hype to another, developers never learn or change, do they?? It feels like yesterday when every single project was moving to Go just because it was the new hype, that was until Rust was born. We are already seeing projects dumping migration to Rust because the grass is not always greener on the other side. We will be seeing this again, "Migrating from Rust to XYZ"

zjy71055

I was a Go engineer for years and have shipped a lot of Go. I never properly learned Rust. Over the past year I've been using AI to write small Rust tools for myself — I barely read the code, and honestly it just works. But for serious projects I expect to maintain long-term, I still pick Go. Today I want code I can actually own and reason about myself. Give it a year or two and I probably won't be writing code by hand at all. Once the AI owns the code anyway, that reason disappears — and at that point Rust's guarantees win. So I suspect I'll end up leaning Rust.