synth VS Rouille, Rust web server middleware

SEEKING FREELANCER | London | Remote

Synth (YC S20) [1] is an open source declarative data generator written 100% in Rust.

We are looking for someone with prior experience writing Rust in production for a 1-to-3 months contract to work with us on our core open-source project.

- Proven experience writing production Rust code, preferably in a large code base

- Knowledge of PostgreSQL at a level sufficient to design and build reliable integration

- Strong knowledge of data structures and algorithms

- Track record of contribution to open-source projects, preferably on GitHub

- Ability to work quickly and rigorously in a fully remote setting

If that sounds interesting, we want to talk to you! Shoot me an email at damien [at] getsynth.com!

[1]: https://github.com/getsynth/synth

Synth | Rust Software Engineer | Full Time or Part Time | London | Onsite(London)/Remote

About us: Synth is an open source declarative data generator (https://github.com/getsynth/synth). We are building Synth with the intention of solving, once and for all, the problem of generating realistic data for testing - helping big companies and small developers avoid the use of production data in testing.

Our mission is to build amazing developer tools that solve data privacy without forcing users to compromise on productivity. We have a few exciting products in our pipeline and we're backed by YCombinator and other great investors. We're based in London and building a remote-friendly culture.

We work exclusively on open source software. This is great because our community is not confined to just our core team and the users, but also includes our contributors - we believe it is way more fun this way.

We're using Rust for our main line of products - and what we would like to see ideally is:

* You have some experience with Rust that has connected you with at least one of: asynchronous I/O, meta-programming or common patterns for concurrency. Having been involved in an open-source Rust project is a bonus!

Take a look at this rust library (which works very well with python modules which generate data in certain formats): https://github.com/getsynth/synth

Putting the finishing touches on a procedural macro to bind Rust code to koto we want to use in synth. Also a blog post about it is on the way.

I'm working on synth https://github.com/getsynth/synth . Also working on a personal project, implementing the tcp protocol in Rust for the fun of it.

We use Rust to build synth, the open source declarative data generator.

Hey HN! We're Synth - a bunch of engineers out of Europe building tooling for developers. We're very excited about what we're working on and wanted to share it with the community.

We've been quite frustrated with the status quo of test data generation - after speaking to tons of other devs we've realised that many people are struggling when it comes to generating realistic looking test data.

Also, where people don’t want to copy sensitive production data to testing environments, data obfuscation can be a huge time-sink.

Enter Synth: a declarative data generator (see our website: https://getsynth.com/, github: https://github.com/getsynth/synth)

Synth enables devs and dev teams to have their application data models as code (basically a hierarchy of files) in their repos. These files can then be used to generate data for a local dev environment, automated testing in CI or even for sharing across organisations. The parameters of generation can also be tweaked to push the data model to its limits for QA, and even scaled for load testing / performance testing.

We're now working on taking the next step, and building a DSL around Synth. The Synth DSL will enable users to concisely define what data should look like and get going.

We're open source and written 100% in Rust. We believe that by making test data be as easy as using production data, we can improve the security and privacy for all of us. We'd love to get more early users as the initial feedback is positive but limited.

Thank you and looking forward to any feedback / ideas about how we can build a better tool for you!

P.S. Synth [launched on HN a while back](https://news.ycombinator.com/item?id=24198114) as an ML solution to create realistic (and safe) copies of your sensitive production data as a service. This approach quickly hit several limitations which couldn't address the use-cases we are trying to solve, happy to go into more details on this if anyone is interested.

I'm currently trying to improve the vtable dispatch in koto (because I want to use it in synth).

Luckily, not all Rust jobs are crypto jobs. I'm in my third Rust job working on synth right now and am 100% happy with it.

Your CRUD web application server almost certainly doesn't need async Rust. Using a blocking HTTP server is not "might be a good idea", it simply is a good idea.

I recommend Rouille for this: https://github.com/tomaka/rouille. In case you are worried about performance, check the benchmark. Blocking Rouille is faster than builtin async server in Node.js.

As you say, the majority of the web ecosystem in Rust has moved to async - but if you’re happy to stray a bit from the beaten path then rouille might do the trick.

In strongly typed languages like Rust, composing smaller libraries is usually quite painless, so you don't need a large framework.

Personally for backend Rust I use rouille[0] for the server (it's very simple and async-free), askama[1] for compile-time HTML templates and (if a SPA is unavoidable, as that is of course always to be avoided if at all possible) yew[2] for client-side WASM.

Now this stack is what I like personally, but there are many options that you can combine, some more full-featured than others. Check out https://www.arewewebyet.org/ for a partial overview.

[0]: https://github.com/tomaka/rouille

[1]: https://github.com/djc/askama

[2]: https://yew.rs/

rouille

I'd like to put in a word for a simple, sync framework such as rouille. The compile times are much, much better, the number of dependencies is much smaller, the stuff it's built on (the standard library) is extensively tested and extremely reliable. Kernel context switches are slower than userspace thread scheduling, but not much slower, and as long as your services aren't just shoving bytes from one place to another (i.e. actually doing some computation) the time taken for a context switch vanishes into noise. A lot of benchmarks test how quickly a web service can move bytes, which (if your business logic is non-trivial) actually isn't the most critical factor.

I don't have any Rust-relevant experience here, but if I wanted to build a web server in Rust and was okay with "reasonable" performance, I'd probably give rouille a try first.

Rouille is fairly solid in my experience. Save the pain of async and spend it building software that works. Honestly with Rust's lack of GC you get predictable response times already.

How would you differentiate it from let's say Rouille ?