Microsoft seeks Rust developers to rewrite core C# code

https://www.theregister.com/2024/01/31/microsoft_seeks_rust_developers/

by yau8edq12i • 2 years ago

207 248 2 years ago

timeon2• 2 years ago

I upvote almost any post "in Rust" here (yeah that's me) but this story went bit too far. It was just one job posting and so many sites acts like MS is going to ditch C#.

fortran77• 2 years ago

That’s funny because I downvote almost any “in Rust” post here!

C# — and garbage collected languages in general — aren’t going anywhere. With the shift to Arm, languages compiled for a runtime interpreter will get even more important for Microsoft.

xedrac6• 2 years ago

Given your username I suspect you're quite a bit older. I've mentored several grey beards on Rust and they weren't at all happy about it, at first. After a few months though, they were some of its strongest advocates. It's hard to not love Rust when you realize just how much pain it saves you from.

zahllos• 2 years ago

I'm a Rust convert, but that needs to be put into context: I do stuff in in cryptography, often on embedded. Prior to Rust I did C and C++ for most of my work. There's also Ada... and it has SPARK, but Ada has never had the level of exposure that Rust has achieved.

But there's all manner of "business systems", e.g. Java/RHEL shops, ".net shops", where GC pauses don't matter, the code is something other than CPU/memory bound anyway,the GC/JIT are mature, and a human writing C++ likely can't do better and will probably do worse. I've seen this with a write-heavy log-ingesting system where the developers used smart pointers everywhere - which internally use atomic reference counting, which implies sync barriers for otherwise entirely unrelated data. I agree, these kinds of places are unlikely to move to Rust - the code writes faster in anything else and runs well. There's also Go, which has a GC but compiles natively, GraalVM, which is AOT compiled Java etc. I definitely agree GC'd languages are not going anywhere.

I'm not sure I agree with C# becoming more important because of ARM, though. I don't think it'll change much - I think shops already invested in certain stacks will mostly stick to them and for all Rust's popularity, it doesn't make sense to implement your CRM in it really. It does, however, make sense to reimplement the C++ parts of the .net runtime and miscellaneous other C and C++ parts of Windows that can benefit from the borrow checker, because it vastly reduces spatial memory safety bugs. There's a massive cost to this, but it's no longer just about about on-prem patching but Azure.

josephg14• 2 years ago

C# — and garbage collected languages in general — aren’t going anywhere.

So what? What does that have to do with rust? There’s no fight between C# and rust where only one language will survive. Both languages are great, and both languages probably have a bright future. C# depends on a lot of low level C/C++ code to function and run fast. I can imagine a future where rust enables c# to get better.

I love rust, but there’s also lots of programs and teams for which c# is a better language choice. So your comment is really weird to me - there’s no reason loving c# should impact your relationship with rust at all.

01HNNWZ0MV43FF6• 2 years ago

Interpreters such as wasm :P

fl0ki3• 2 years ago

With the shift to Arm, languages compiled for a runtime interpreter will get even more important for Microsoft.

How's that? Apple and its app ecosystem just ship universal binaries, so native, heavily optimized x86_64 and aarch64 code is always ready to go with no added fuss for the user.

You could certainly argue this makes already-large binaries even larger, but users care much more about CPU & RAM efficiency than on-disk binary size. Especially on ARM machines that many people buy for battery efficiency in the first place.

On Linux you don't even bother with universal binaries because you just ship the entire package repository already built for the target CPU. It's only more fuss for the user if they need to pick specific packages from outside their distro.

Has Microsoft still not managed to make something similar work on Windows?

jauntywundrkind• 2 years ago

May every one of us attain sufficient popularity as to attract people who blankety hate you without even bothering to supply reason or argument. May you be so popular & doing such good things people feel the need to downvote everything they see about it on sight.

Actually personally I wish we could identify such people & ignore their votes. Actually personally I wish we could take persistent downvoters & fire them into the sun. I don't see or understand why anyone would let contempt so deeply into their soul. The world is no zero sum and I have little patience for those would seem to go out of their way to deny & reject others.

oaiey• 2 years ago

Totally agree. The .NET team itself is probably costing above 100 million every year, probably more. Microsoft is not ditching .NET, they are heavily investing it.

The office division is implementing some code in Rust while the same division just posted a success story of their usage of migrating some low latency server code to .NET Core.

Microsoft is a big company and like any other they use JS, TS, Rust, C++, Python, Go and so on. The only thing they do not use is Java ... And I am not 100% confident there.

So let us congratulate Rust for entering the office domain and stop writing swan songs about .NET.

rileymichael• 2 years ago

They use a ton of java, they even have their own distro. In fact, they answer this question on its landing page (https://www.microsoft.com/openjdk):

Java at Microsoft spans from Azure to Minecraft, across SQL Server to Visual Studio Code, LinkedIn and beyond! We use more Java than one can imagine.

bigtex4• 2 years ago

There is a reddit post where a dotnet developer on the MSFT team details why they are moving certain processes to Rust. TLDR, it is all about performance that scale.

atesti2• 2 years ago

Does anybody have a link?

bigtex4• 2 years ago

I will try to find it today if I have a chance. I think it was on cscareerquestions or dotnet.

bigtex4• 2 years ago

Here is the reddit link, https://www.reddit.com/r/dotnet/comments/1aezqmg/comment/ko8...

rubyfan• 2 years ago

Can they start by not needing a multiple gigabyte download and admin rights to get the rust compiler to work on Windows?

vijaybritto2• 2 years ago

Is that needed because the compiler accesses some higher privileged APIs?

Measter• 2 years ago

The MSVC-based compiler doesn't come with a linker, so you need the MSVC build tools to get it. One of the ways to get the build tools is to install Visual Studio, which is fairly large.

Thaxll• 2 years ago

Why would a compiler needs any privileges, it's like a text editor

itishappy• 2 years ago

Does C# not require a multiple gigabyte download and admin rights?

FWIW I've gotten rust working with the GCC build tools on windows without admin rights, thought it's admittedly somewhat janky.

metaltyphoon• 2 years ago

Not C# doesn’t need multiple gigabytes and admin rights. Dotnet tooling != Visual Studio

thrownaway561• 2 years ago

Just hire Yehuda Katz

rahen• 2 years ago

What's the point of rewriting from C# to Rust, as C# is performant enough and already has memory safety? What will offset the huge rewrite cost?

chiph• 2 years ago

I suspect this is the .NET runtime + libraries, not applications written in C#.

Merad2• 2 years ago

No, they're looking at migrating some core Office 365 services to Rust. This is the job posting: https://jobs.careers.microsoft.com/global/en/job/1633482/Pri...

At the scale of O365 it totally makes sense to look at a high performance non-GC language for your core systems that see the most traffic (I say this as a .Net dev).

dragonwriter• 2 years ago

C# doesn't have ownership/lifetimes and the kind of safety that comes with them.

Also, at the scale of Microsoft’s core global services, when you are paying for the processing, fast enough (or “CPU efficient enough”) isn't the same as with common apps. Even small efficiency gains are going to yield sufficient savings to be worth a fair amount of developer time.

hgs3• 2 years ago

C# doesn't have ownership/lifetimes and the kind of safety that comes with them.

Could you elaborate? C# has a garbage collector for tracking resources.

jmull3• 2 years ago

C# doesn't have ownership/lifetimes and the kind of safety that comes with them.

That's not really true.

Like rust, C# is memory safe, although it comes at it in a very different way.

"safe" rust does inherently prevent a certain kind of race condition in multi-threaded code that C# does not, thought that's more of a nice incremental improvement, not a fundamental one -- i.e. it doesn't make your multi-threaded code thread-safe, but it does prevent a one type of thread safety violation.

krona• 2 years ago

C# doesn't have ownership/lifetimes and the kind of safety that comes with them.

I believe .net Core has supported several forms of escape analysis for quite a while.

charles_f• 2 years ago

Almost all of the services I've seen at Microsoft were built in C#

packetlost• 2 years ago

C# is performant enough

until it isn't. At Microsoft's scale, I imagine performance is actually a major concern for certain pieces of applications.

fbdab1032• 2 years ago

Considering the Microsoft consumer software that burns cycles to do trivial things (Teams, OneDrive, pick your favorite example). I do not think language performance should be a compelling argument.

tracker119• 2 years ago

There's a difference in resources on client machines and resources on thousands of servers in server farms.

LeFantome• 2 years ago

How have you established that there is a “huge rewrite cost”?

Despite other comments here, I see nothing in the post that says “we are moving away from C# and rewriting everything in Rust!”

Microsoft is using Rust in Windows as well. They have given examples of how. In that case, they are not “rewriting Windows” but rather targeting specific components that benefit from the characteristics of Rust. Those components are just part of the larger application that is still primarily written in C.

C# easily with C and therefore with Rust. They interoperate well. So it seems likely that MS is following the same plan and rewriting specific components of the larger system that would benefit from Rust.

tracker119• 2 years ago

Who says they are? Probably depends and varies by the application.

One example I could think of is if it's currently a SaaS on Azure, but it needs to be portable enough for a version to run in a low end Arm IoT device.

Or if it's deployed to thousands of servers and taking excessive memory or CPU resources for a monitoring agent. Or GC freezes affecting other adjustments systems.

There are plenty of reasons to retire C# to Rust.

gigatexal• 2 years ago

Why is MS so hyped on Rust? It’s good but doesn’t it have its caveats? It seems they’ve become Rust zealots.

marcosdumay• 2 years ago

It’s good but doesn’t it have its caveats?

Compared to C#, it's a low level language, where you have to be concerned with a lot of details.

But then, I'd bet this is for replacing bad C# that does low level tasks, that nobody sane would write but MS pushed for anyway because they were hyping C#.

tialaramex• 2 years ago

Office 365 is was introduced in 2010. So when it was created Microsoft had two reasonable options:

1. Accept the performance penalty from using a safe garbage collected language (such as their own C#) which is slower which may make the service less attractive and more resource hungry which means more expensive to run at scale.

2. Accept the correctness penalty from C++ which delivers good performance but will cause an endless stream of bugs, some very hard to diagnose.

Rust makes this much easier, because you aren't paying the correctness penalty, your Rust will probably have the same or fewer correctness bugs as your C#, and yet you get the good performance you'd have wanted from C++.

For a 2010 product Rust was not an option, but presumably at some point in the last say five years, Microsoft did the maths and worked out that unless they're killing Office 365 soon or somehow C++ magically becomes safe with no work, a transition to Rust is cost effective.

jimberlage• 2 years ago

MS has lots of battle scars from the security headaches they went through in the 2000s/2010s.

01HNNWZ0MV43FF6• 2 years ago

In 2007 they were .NET zealots and now .NET is old guard

tracker119• 2 years ago

There plenty of ongoing development and support for .Net, it's much less likely a matter of age, as it is handling more requests per server.

lucasRW• 2 years ago

I can understand the move from unmanaged C to Rust for security reasons, but C Sharp to Rust ? Am I missing something here ?

jonhohle• 2 years ago

Performance reasons.

tracker119• 2 years ago

Reduced memory and CPU utilization at scale most likely.

mmastrac2• 2 years ago

I love writing Rust, but I was really surprised by how difficult it was to find a job _actually_ writing Rust.

I'm happy to see the increased activity in the space, but searching for a job in Rust is probably still 10x harder than C or C++.

It worked out in the end, and I'm happy to be getting paid to be writing Rust every day, but I hope that the market for Rust jobs continues to grow -- ideally even faster than it has been.

rockwotj• 2 years ago

On the reverse side of things, trying to find a C++ dev is usually harder than finding people who want to write Rust.

mmastrac2• 2 years ago

I suppose C++ devs are on the correct side of the demand curve, unlike myself. :D

I was _really_ tempted to take a C++ job at some point but I held out.

secondcoming3• 2 years ago

Yup, we were hiring C++ devs recently and it was quite common for candidates to mention Rust. Did they not read the job description??? Immediate red flag.

ClimaxGravely2• 2 years ago

It's been pretty great having one of my primary languages c++ lately wrt job opportunities.

diego_moita2• 2 years ago

Agree, I am still looking for a Rust position, although I have more than 3 years of experience with it.

And yes, it is very hard.

It seems Rust is in a chicken/egg position: employers avoid it because "there are few developers", developers avoid it because "there are few jobs".

Until recently the majority of Rust jobs were blockchain stuff. Now I see a rise in network infrastructure and security.

godzillabrennus• 2 years ago

Seems like RUST needs work to become easier to learn. Hard for a business to take a risk on using it (outside of a use case absolutely needing a memory safe language) if the talent pool is shallow.

FlyingSnake• 2 years ago

I know some teams that are hiring Rust devs. Please feel free to ping me if you would like to know more.

xedrac6• 2 years ago

The trick is to introduce Rust wherever you're at, assuming it's a good fit for the task. This may be harder to do if you don't have enough influence.

tayo422• 2 years ago

Quick way to be annoying and unlikeable at work.

The times I've seen rust introduced, and tried it my self, it introduces a whole bunch of related tech debt. Like hacks to make builds work

jonnytran2• 2 years ago

Yes, I did this at my startup. Fast forward a few years, and now the company has more Rust code than Python, and the majority of the company's IP is in Rust.

I suggest beginning with small, one-off things that don't have much impact. People, even developers, tend to shy away from things that aren't familiar. By introducing Rust in a small, low-risk way, it helps people get familiar with it. They get to build familiarity with building Rust projects, navigating the project structure, and reading docs. I submit pull requests that get people to read Rust code, even if it's just to say "looks good". Their familiarity builds slowly over time, meaning they'll be less triggered by seeing Rust in a larger, more impactful project down the road.

How do you boil a software developer? Slowly.

If they give Rust a chance and your team has a champion to guide them, they'll see its merits. I think a lot of people come to Rust for the performance, but that's not why they stay.

TrackerFF• 2 years ago

We acquired a product last year, where the entire back-end was written in Rust.

Unfortunately, Rust developers were hard to get by, and we didn't have any internally that could maintain the Rust code at such scale.

The entire back-end ended up being re-written.

codetrotter• 2 years ago

Nooo :'(

beeboobaa2• 2 years ago

What happened to the developers who wrote the back-end in the first place?

ducktective• 2 years ago

The entire back-end ended up being re-written.

In Go, I presume?

rowanG0772• 2 years ago

Why not just learn rust? It really is not that exotic to learn. I doubt it is faster to rewrite it.

imetatroll2• 2 years ago

I honestly wish I could have been in that boat because I crave the opportunity to use rust on the job.

davidmurdoch3• 2 years ago

There are tons of Rust jobs in blockchain.

kaycey2022• 2 years ago

I’m interested. Can you tell me what do rust developers build or work on in this space? Where do you start networking and build the demonstrable skills to get into blockchain?

bmoxb• 2 years ago

Yes, that's the issue.

surajrmal• 2 years ago

It's equally difficult to try and hire a team of folks who know rust. There is also a lot of legacy code which doesn't cleanly interop with rust (cxx and the like are not sufficiently easy to bridge the gap). It would be much easier to convince your existing team to start using rust where it makes sense than it would be to switch jobs in search of one which primarily uses that. Over time both of these problems will diminish, but that'll likely take another decade.

summerlight• 2 years ago

One thing is that a large fraction of C/C++ devs are hired by big companies. And those tend to have a large amount of legacy code and in-house tooling. Adding one more language to such big ecosystem can be a significant investment than kicking off a new project from scratch, so they need a good transition story to convince stakeholders and get actual funding(=more headcount/jobs).

I think Rust has reached to the level where many of us agree on that it's probably a good idea to move on, but probably not many of us have a good idea on how to do that. Hopefully some teams are eager to do that, so we will see some success story soon then more and more teams will explore such possibility.

bobajeff• 2 years ago

I'm not totally sold on rust as a language but I have to admit the tooling and ecosystem is really nice. I'm noticing that I'm increasingly using more stuff built with it.

I'm also not sold on zig either for many of the same reasons. I prefer my low level languages to be smaller like c. I think that might be true for languages higher level languages too. I just don't like to have to down a lot of documentation on hundreds of different features and concepts behind them.

kiririn• 2 years ago

The tooling/ecosystem looks probably great for developers actively creating with it, but for developers ‘consuming’ it (downloading some foss from github and changing a couple of lines) it leaves a lot to be desired. Not being able to ‘apt install’ a working toolchain on Debian for example - it’s already too outdated after just a year

tracker119• 2 years ago

That's pretty true of a lot of development tools on Debian.

wslh• 2 years ago

Hi @dang, regarding HN karma, what happened to the karma points if a user posted the same article just twenty hours earlier? (◔_◔) [1]

[1] https://news.ycombinator.com/item?id=39232275

Sparkyte• 2 years ago

I imagine it comes down to the handling of threads vs anything else. Technology is rapidly adopting the more cores strategy of technology since we are hitting some IPC limitations and in the server space more cores is better.

munchler• 2 years ago

.NET supports asynchronous code very well, so that hardly seems like a likely reason for rewriting in Rust.

pdimitar8• 2 years ago

.NET supports asynchronous code very well

Work-stealing task schedulers?

neonsunset11• 2 years ago

Multi-core scaling (in particular within GC) is one of the strongest points of .NET (for example, Go used to have poor scaling on many-core systems (has this changed in 2024?) while in .NET the throughput would continue scaling linearly)).

pdimitar8• 2 years ago

I really doubt that this is true, might be your bubble. Have you dabbled in Erlang/Elixir? Your standards would increase substantially if you did.

TideAd• 2 years ago

I find this very strange, Microsoft has a lot of big internal high-performance services written in C#.

You have to be intentional about some things - largely making sure objects are very short-lived or very long-lived, to avoid long GX pauses. But .NET performs much better than it did 10-15 years ago and I can't think of a fundamental reason why you'd rewrite in Rust.

dtx1• 2 years ago

Might not be all about performance but about security aswell.

zozbot2343• 2 years ago

The Rust folks are working on experimental codegen for the CLR https://fractalfir.github.io/generated_html/rustc_codegen_cl... leveraging the existing CIL/CLR support for "unsafe" languages. Once that work is complete, you should be able to rewrite C# code to Rust on a very fine-grained basis (a single function at a time or thereabouts), just like you can when porting C to Rust. Of course, you'll also be able to remove the CIL/CLR dependency altogether if you're left with 100% Rust code, and compile to a binary just like in ordinary C/C++.

jasonjmcghee2• 2 years ago

Are there any rust books that have the focus of “ok you are productive in rust, this is what you should know / do to write proper rust”?

Edit: ok found https://github.com/sger/RustBooks

Any specific recommendations?

sn9• 2 years ago

It sounds like you want Rust for Rustaceans: https://nostarch.com/rust-rustaceans

jasonjmcghee2• 2 years ago

Thank you

psuresh• 2 years ago

Expect MS own clone of rust like C#(for java) or typescript (extended js) in future

tracker119• 2 years ago

I think they already have this internally. That said, I believe they already have board seats and are large contributors to the rust foundation.

atesti2• 2 years ago

Does anybody know more about the "Substrate App Platform group"?

As far as I understood it, actually Microsoft Exchange and ESENT powers a lot of Office 365, e.g. the compliance tools, the search and e.g. teams chats. Next to it is another pillar: Sharepoint, which is also exposed as OneDrive and is based on SQL server.

Is substrate or has it been part of Exchange?

bigtex4• 2 years ago

Here is a link to a user on reddit claiming to work at Microsoft going into more detail, https://www.reddit.com/r/dotnet/comments/1aezqmg/comment/ko8...

WuxiFingerHold• 2 years ago

Below some background from a Microsoft employee (https://www.reddit.com/r/dotnet/comments/1aezqmg/comment/ko8...):

Makes perfectly sense. Rust is a replacement for ultra performance sensitive parts that might have been written in C/C++ before, but not a replacement for C#.

---------------------------------------------------------------------------------------------------------

Hey there!

I work at Microsoft. I can shed a bit of light here.

We use .NET for TONS of things. Absolutely tons of different products and services. I'm on the Office 365 side of the business, currently managing Deployment for all of the hundreds of services that roll out across the world... And we use .NET extensively.

I'm starting my new position managing a team that does routing next week. They have some things that are extremely performance critical. As others have pointed out, we're talking about supporting services and traffic literally across the planet. When it comes to optimizing, they will find ways to squeeze out what they can.

There are languages like C and C++ that get used for some extreme use cases like I mentioned. Reducing as much overhead as possible in certain situations even leads to .NET apps with unmanaged pieces included with them.

There's been a lot of hype around Rust, and for good reason. But it's a system language. It's not like Microsoft is about to go rewrite millions and millions of lines of code and toss out C# (for anyone getting nervous ). They're just being pragmatic and using an effective tool for the job.

Hope that offers some clarity.

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Microsoft seeks Rust developers to rewrite core C# code

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