Prime Video with Alexandru Ene

46 snips

Oct 2, 2025

Join Alexandru Ene, Principal Engineer at Prime Video, as he delves into the fascinating transition of their UI from JavaScript to Rust. With a background in game development, Alexandru highlights how Rust's performance and safety elevate Prime Video's infrastructure. He discusses the challenges of ensuring a smooth user experience on various devices, the impact of WebAssembly, and the strategic approach of gradual migration. Plus, learn about the importance of onboarding engineers with an adaptable mindset and the unique intersections between UI and game engine design.

Ask episode

AI Snips

Chapters

Transcript

Episode notes

ADVICE

Choose Smooth Tooling First

Favor toolchains with fast, reliable iteration to onboard engineers faster.
Adopt ecosystems (like Cargo) that make "cargo new" and "cargo run" trivial compared to complex C++ build setups.

ADVICE

Start Small And Win Big

Start Rust adoption with a small, self-contained project that has a clear performance pain point.
Use that win to build trust and justify gradual, controlled expansion across teams.

ANECDOTE

Relaxed Code Reviews With Rust

Code reviews became less stressful after adopting Rust because memory-safety issues were mostly handled by the language.
Alexandru still reviews C++ for a tiny native layer where memory concerns remain central.

Get the Snipd Podcast app to discover more snips from this episode

Get the app

Are you one of over 240 million subscribers of Amazon's Prime Video service? If so, you might be surprised to learn that much of the infrastructure behind Prime Video is built using Rust. They use a single codebase for media players, game consoles, and tablets. In this episode, we sit down with Alexandru Ene, a Principal Engineer at Amazon, to discuss how Rust is used at Prime Video, the challenges they face in building a global streaming service, and the benefits of using Rust for their backend systems.

About Prime Video

Prime Video is a streaming service offered by Amazon that provides a wide range of movies, TV shows, and original content to its subscribers. With over 240 million subscribers worldwide, Prime Video is one of the largest streaming platforms in the world. In addition to its vast content library, Prime Video also offers features such as offline viewing, 4K streaming, and support for multiple devices. On the backend, Prime Video relies on a variety of technologies to deliver its content, including Rust, which is used for building high-performance and reliable systems that can handle the demands of a global audience.

About Alexandru Ene

Alexandru worked on the transition of Prime Video's user interface from JavaScript to Rust. He has been with Amazon for over 8 years and previously worked at companies like Ubisoft and EA. He has a background in computer science and is an active open source maintainer. Alexandru lives in London.

Links From The Episode

Ferris Makes Emulators Ep.001 - The Journey Begins - First episode of a famous series where Jake Taylor wrote a Nintendo 64 emulator in Rust from scratch
CMake - Very common build system used in C++ applications
Conan - C++ Package Manager community project
C++ Smart Pointers - Still a footgun
Herb Sutter: The Free Lunch Is Over - The seminal 2005 paper that highlights the importance of concurrency, well past C++'s mainstream adoption
Rust in Production: cURL - Baseline library used everywhere, written in C, but performant and safe
Prime Video Platforms - One app runs on all of these
WebAssembly (WASM) - Enabling Rust code with good performance that you can still download and run like JavaScript, avoiding the need for firmware updates on some devices
Entity Component System - Used in the UI Rust code for pages in the app
Bevy - Game engine written in Rust
Leptos - UI framework that makes reactive programming in Rust easier
tokio - The de facto standard async runtime for Rust
SIMD - A nice feature set some CPUs support
WebAssembly Micro Runtime - A tiny WASM runtime well suited for IoT platforms
WebAssembly Working Group

Official Links