About us
Ruby Labs is a leading tech company that creates and operates innovative consumer products. At Ruby Labs, we are looking for a Senior Desktop Engineer to own and drive a new cross-platform desktop product from first commit to production. The application is not a wrapped web app: it captures system and microphone audio in real time, renders an always-on-top overlay across the user's workspace, registers integral shortcuts, and integrates with the operating system at a level that requires native code on both macOS and Windows. Our architecture is Electron for the application and UI layer, with native modules and helper processes in Swift and C++ where the platform requires it. You will own that boundary, deciding what belongs in TypeScript, what belongs in native code, and making the two halves behave as one reliable product. You will operate as the senior technical voice for desktop within your team, setting the engineering standard for the platform. Desktop Application & Engineering Quality Own the Electron architecture end to end — main, renderer and helper processes, IPC design, context isolation, process lifecycle — and deliver major features within agreed timelines. Build transparent, frameless, always-on-top overlay windows that behave correctly across full-screen spaces, multiple displays and mixed-DPI setups, alongside global shortcuts, tray presence and low-latency UI under continuous background load. Design a clean platform abstraction in TypeScript so the macOS and Windows implementations stay isolated and independently testable, and write idiomatic Swift and C++ in the native layer. Keep the product reliable: defensive handling of unstable platform APIs, tests and code reviews, performance, memory and battery budgets,



and remediation of security-review and penetration-test findings within agreed severity SLAs. Node addons (N-API / node-addon-api) and out-of-process helpers in Swift and C++. Implement real-time system audio capture — Core Audio process taps and ScreenCaptureKit on macOS, WASAPI loopback on Windows — including device change handling, format negotiation and graceful recovery from driver-level failures. Integrate with the Accessibility API (AXUIElement) on macOS and UI Automation on Windows to read application context reliably. Own the IPC protocol and lifecycle between Electron and the native helpers, and keep the application working as Apple and Microsoft change their platforms. Own code signing and notarization on macOS — hardened runtime, entitlements, nested binary signing, provisioning profiles — and Authenticode signing, SmartScreen reputation and antivirus false positives on Windows. Design the permission onboarding flow — microphone, system audio, screen recording, accessibility — so that grant rates stay high and failure states are recoverable. CI matrix builds, signing from CI with HSM-backed certificates, auto-update, staged rollout and rollback. Own crash reporting and production telemetry for the desktop client, and act on what it tells you. 6+ years of software engineering experience, including production-grade TypeScript/Node.js. ~3+ years building and shipping Electron applications to real end users,



not internal tools or proofs of concept. ~ Hands-on native macOS development in Swift and/or Objective-C, with AppKit and at least one system-level framework such as Core Audio, AVFoundation, ScreenCaptureKit, or the Accessibility API. ~ Practical experience writing native Node addons (N-API / node-addon-api) or bundling and communicating with out-of-process native helpers. ~ Demonstrated experience with macOS code signing, notarization, entitlements, and the TCC permission model — you have debugged a rejected notarization and know how to read the log. ~ Working knowledge of the Windows desktop platform: Real-time audio pipelines — buffering, resampling, mixing multiple sources, or streaming to speech-to-text services. Signing from CI with hardware-backed certificates (Azure Key Vault, DigiCert KeyLocker, or similar), and antivirus whitelisting or SmartScreen reputation building for a new product. Auto-update infrastructure such as Squirrel, electron-updater or Sparkle, including staged rollouts. Crash reporting and symbolication for native code (Crashpad, Sentry, or similar). Ruby Labs operates within the CET (Central European Time) zone. Remote Work Environment: Paid National Holidays: Celebrate and relax on national holidays with paid time off to unwind and recharge. Flexible Independent Contractor Agreement: Benefit from tax advantages, networking opportunities, reduced employment obligations, and the freedom to work from anywhere. Read more about it here: Life at Ruby Labs At Ruby Labs, we move fast, aim high, and expect the same from our team. If you’re hungry to achieve, motivated by impact, and want to grow at the speed of your own ambition, Ruby Labs offers the platform to make it happen. LI-Remot

📌 Senior Desktop Engineer (España)
🏢 Ruby Labs
📍 España