Senior Software Engineer, Cobalt

About the Role:

We are hiring a Senior Software Engineer to build Tubi's native app runtime for connected TVs on Cobalt, the lightweight, open-source browser engine behind YouTube on living room devices. You will own the layer between Tubi's React app and the device: the Cobalt engine, its Starboard porting layer, and new native components we write in C++ and Rust.

The goal is a Tubi app that launches faster, uses less memory, and behaves the same on every device, starting with Fire TV and expanding to other CTV platforms. This is a hands-on, high-ownership role on a small team, working closely with our web engineers, QA, and device partners.

This is a hybrid role which is two days in the SF office.

What You'll Do:

• Build, integrate, and ship Cobalt as the runtime for Tubi's CTV apps, packaged as a native library inside our Android (Fire TV) app and later on other platforms
• Implement and maintain Starboard platform integrations: graphics, input, audio/video playback, DRM, and system services
• Write new native modules in modern C++ and Rust, including safe FFI boundaries between the two
• Drive startup and memory performance on low-end, memory-constrained devices (1 GB RAM class): profile, measure, and fix
• Keep us current with upstream Cobalt releases, track and contribute fixes upstream, and manage security patches for the engine we ship
• Work with media and playback teams on video pipeline needs such as demuxing, adaptive streaming, and ad playback
• Build tooling that runs the Tubi app on Cobalt on developer machines and in CI, so we can test UI and automation without a device farm
• Work directly with device partners' engineering teams on platform issues
• Mentor engineers and raise the team's native and systems engineering bar

Your Background:

• 6+ years of professional software engineering, most of it in systems or native code
• Expert-level modern C++ (C++17/20): memory management, concurrency, templates, and debugging large codebases
• Strong production experience in Rust: ownership and lifetimes, async, unsafe code, and C/C++ interop (FFI, bindgen/cxx)
• Experience with large C++ build systems (GN/Ninja, CMake, or Bazel) and cross-compiling for ARM and embedded Linux or Android targets
• Hands-on performance work: profiling CPU, memory, and startup time with tools like perf, Perfetto, or heaptrack, and turning findings into measurable wins
• Comfort debugging on real hardware: Android NDK, adb, native crash analysis, and symbolication
• Clear written communication and a track record of leading technical initiatives across teams

Nice to Have

• Experience with Cobalt, Starboard, Chromium, or another browser engine (Blink, WebKit, Servo)
• JavaScript engine internals, especially V8: code caching, snapshots, or GC tuning
• Graphics on embedded devices: OpenGL ES, Skia, or WebGPU
• Media pipelines: MSE/EME, ExoPlayer or native players, demuxers, Widevine or PlayReady DRM
• Shipping on TV platforms such as Fire TV, Android TV, Samsung Tizen, LG webOS, or Roku
• Open-source contributions to C++ or Rust projects
• Enough React and TypeScript to work with the web app running on top of the engine