Senior Software Engineer, Cobalt

Description

The team builds the native runtime that lets the company's streaming app run on connected TVs. The runtime uses Cobalt, a lightweight open-source browser engine that also powers YouTube on living room devices.

You will own the layer between the company's React app and the device. That layer includes the Cobalt engine, its Starboard porting layer, and new native components written in C++ and Rust.

The aim is an app that starts faster, uses less memory, and behaves the same on every device. Fire TV comes first, with other CTV platforms to follow.

The company is a free streaming service with over 100 million monthly active users, based in San Francisco. It is a small, hands-on team that works closely with web engineers, QA, and device partners.

This role is hybrid and requires two days a week in the San Francisco office.

Responsibilities

• Build, integrate, and ship Cobalt as the runtime for the CTV apps, packaged as a native library in the Android app for Fire TV and later on other platforms.
• Implement and maintain Starboard integrations for graphics, input, audio and video playback, DRM, and system services.
• Write new native modules in modern C++ and Rust, including safe FFI boundaries between them.
• Improve startup time and memory use on low-end devices with 1 GB of RAM by profiling, measuring, and fixing.
• Keep up with upstream Cobalt releases, track and contribute fixes upstream, and manage security patches for the engine you ship.
• Work with media and playback teams on video pipeline needs such as demuxing, adaptive streaming, and ad playback.
• Build tooling that runs the app on Cobalt on developer machines and in CI, so UI and automation can be tested without a device farm.
• Work directly with device partners' engineering teams on platform issues.
• Mentor engineers and raise the native and systems engineering standard across the team.

Requirements

• 6+ years of professional software engineering, mostly in systems or native code.
• Expert-level modern C++ (C++17/20), including memory management, concurrency, templates, and debugging large codebases.
• Strong production experience with Rust, including ownership and lifetimes, async, unsafe code, and C/C++ interop using FFI, bindgen, or cxx.
• Experience with large C++ build systems such as 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 such as perf, Perfetto, or heaptrack, with measurable results.
• Comfort debugging on real hardware using the Android NDK, adb, native crash analysis, and symbolication.
• Clear written communication and a record of leading technical work across teams.
• Experience with Cobalt, Starboard, Chromium, or another browser engine such as Blink, WebKit, or Servo.
• JavaScript engine internals, especially V8, such as code caching, snapshots, or GC tuning.
• Graphics on embedded devices using OpenGL ES, Skia, or WebGPU.
• Media pipeline experience with MSE/EME, ExoPlayer or native players, demuxers, or Widevine or PlayReady DRM.
• Experience 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 the engine.
• LI-CL1
• LI-Hybrid

Conditions

The pay range is $186,400 - $266,300 USD per year. The final offer depends on education, skills, experience, and location, and is listed here to meet state and local pay disclosure rules.

The role is in a high cost labor market such as Los Angeles, New York City, or San Francisco.

The role is hybrid, with two days a week in the San Francisco office.

Equal opportunity applies to all candidates.

Benefits

• Eligible for an annual discretionary bonus and a long-term incentive plan.
• Medical, dental, and vision coverage, insurance, a 401(k) plan, and paid time off, subject to the applicable plan documents.
• Salaried and exempt staff receive flexible time off for personal matters instead of the parent company's vacation policy.
• Non-exempt US staff follow the parent company's vacation and sick time policy.
• Full-time employees get 12 weeks of paid bonding leave within the first year after birth, adoption, surrogacy, or foster placement, on top of government leave and the parent company's short-term disability policy. Pay is 100% covered through state, city, and federal leave and wage-replacement programs plus company contributions.
• Full-time employees receive a monthly wellness reimbursement.