This is the pilot episode of our new interview series Meet the Developer, where we talk to the people behind anti-censorship tools. Our goal is to shine a light on the developers whose open-source solutions help millions of people stay connected.
In this first episode, we sit down with Toby, the lead developer of Hysteria, to discuss the project’s origins, technical challenges and his perspective on internet censorship.
Let’s start with an introduction. Tell us who you are and what you do.
Just call me Toby. I’m a software engineer. Previously, I have worked for a large company. But right now, I’m a co-founder of a startup with some friends.
Nice to meet you Toby! Would you like to share what type of startup it is, or is it a top secret project?
We are still in stealth mode.
Why did you decide to develop Hysteria?
It was originally a project I developed for myself when I was in college.
China’s global Internet connectivity has been notoriously bad for as long as I can remember (still not any better right now). Not just in the sense of censorship, but also in terms of connection quality.
For example, if you have a server in the US and want to connect to it from China, expect over 10-20% or more packet loss.
So if you set up a proxy server in another country to circumvent censorship, it would be painfully slow (the most popular tools back then were GoAgent and later Shadowsocks).
So Hysteria began as an attempt to improve my speed for watching YouTube videos.
It’s always great to see developers building something to solve their own challenges. I can relate to the packet loss issue. Either you suffer the packet loss, or you have to purchase an expensive server with CN2 routing, which will cost a lot.
What was the biggest challenge you faced while developing Hysteria? Did you ever feel like giving up at some point?
Yup, originally it wasn’t called Hysteria. It was Dragonite.
It started 8 years ago as a custom, reliable transmission protocol based on UDP in Java (QUIC didn’t exist back then)
Developing and debugging this thing just to get it to work is still one of the most intensive projects I’ve done to this day.
The hardest part was correctly implementing reliable transmission mechanisms, like loss detection, flow control and retransmission.
I spent months debugging it in a college dorm every night.
Have you ever faced any threats or pressure from governments that oppose anti-censorship tools, such as China, Russia, or Iran?
Not personally. Mostly because my project was pretty obscure and by the time it took off, I already left China. I do get phishing emails trying to access my GitHub account and stuff, but it’s probably not due to my project.
Where do you think internet censorship is heading in the future?
I actually think Internet censorship will be less on blocking websites and more on censoring content on the platforms through laws (and sometimes other methods of pressure)
There are multiple factors why I think China’s approach of blocking foreign services outright will not work in most other countries:
- everything is encrypted (TLS) and infrastructure is increasingly centralized (think how many sites use AWS/Cloudflare) so it’s increasingly difficult to block a specific thing without collateral damage
- social media platforms are run by companies purely for profit so they have every incentive to meet whatever government demands in order to keep doing business in a country
- VPN and proxies have become normalized and legit big business (ExpressVPN/NordVPN etc.) that bypassing censorship is trivial without a comprehensive censorship system like the GFW
Do you use AI tools in your development workflow? Which ones do you find most useful or trustworthy, and what’s your view on the current state of AI in tech?
Yeah, I heavily use Cursor and Claude Code.
I would say Cursor is still the best in terms of UX because of the IDE integrations.
Model-wise, I think GPT-5.2 is still the most competent model. As for my opinion on AI in tech, I would love to see AI applied more in the physical world and not just in coding/writing.
What GUI client do you use for Hysteria on your devices?
I use sing-box on Android (don’t take this as an official recommendation).
I don’t use GUI on desktop.
What is your opinion on other censorship projects and different cores like Xray, v2fly and sing-box?
That’s quite a broad question. I know the developers behind most of those projects. I like the fact that they all have different approaches and unique characteristics. This flexibility and dynamism is exactly what we need to beat the GFW.
Google will block sideloading of unverified Android apps next year. How much do you think it will affect developers? We have already seen a drop in clients, because of ID verification for Play Store. I think v2rayNG is one example, because devs don’t want to share personal information with Google and make it public on top of that.
Yeah, I think it will have a big impact, especially on niche communities like this.
And the fact that Google is clearly trying to copy Apple and turn Android into a closed ecosystem worries me a lot. We seriously lack a truly free and open smartphone OS.
For readers who want to contribute to Hysteria, what kind of contributors are you looking for right now?
Any kind of meaningful contribution is welcome, but I want to rework the current BBR congestion control in particular.
Is there anyone you’d recommend we talk to next? Feel free to pass the torch :)
Have you talked to the developer of sing-box?
That’s a good suggestion. We will be in contact with the sing-box dev.
Many thanks to Toby for joining us and sharing the story behind Hysteria!