Senior Android Engineer (Contract) - Slack Voice...

ecosystem. Engagement type: Contract (via contractor hiring firm). Immediate start. Bar for all, You will build and ship the Android surface of Slack’s voice agent experience, to the same production bar

as the iOS role above: modular, tested, performant code that could land in Slack’s production Android

codebase.

What you’ll do

• Design and implement the voice agent’s Android client: voice capture/playback, real-time audio

streaming, conversational UI, and deep integration with the existing Slack Android app.

roles: Production-ready code and craft that meets the standard of the Slack production codebase. Slack

is an extremely design-driven organization - every hire, engineering included, must have demonstrable

design sensibility and experience working within (or adjacent to) a mature design system.

Preferred candidate backgrounds (all roles): Prior work at companies with a strong, recognized

design language - e.g., Apple, Airbnb, Duolingo, Linear, Figma, Notion, Stripe, Cash App/Block,

Headspace, Robinhood, Vercel. For the voice-agent domain specifically, experience at OpenAI, Charac

ter.ai, Replika, or other conversational/voice UX products is a strong plus, Must-have

• 6+years Android, expert-level Kotlin (Coroutines and Flow are non-negotiable).

• Production experience with Jetpack (ViewModel, Room, Navigation, Lifecycle), Jetpack Com

pose strongly preferred, SQLDelight or Room for persistence, and Dagger/Hilt dependency

injection.

• Strong grasp of MVVM + repository pattern in a large, modularized (Gradle multi-module)

codebase.

• Audio/voice domain experience: AudioRecord/AudioTrack, Media3/ExoPlayer, audio focus

and session management, real-time/streaming audio, ASR/TTS SDK integration.

• Shipped and maintained apps at 100K+ MAU minimum; 1M+ MAU strongly preferred -

with crash-free discipline, profiling (Android Studio Profiler, Perfetto), and staged rollout experience

via Play Console.

• Testing: JUnit, Espresso, MockK/Mockito, Robolectric; Paparazzi/screenshot testing a plus.

• CI/CD: fastlane, plus Buildkite or GitHub Actions (Bitrise/Codemagic acceptable equiva

lents); Firebase App Distribution / Play internal tracks, feature flags, staged rollouts. Nice-to-have

• Prior work at a design-forward company (see list above).

• On-device ML / LLM client experience (ML Kit, TensorFlow Lite, WebRTC, streaming token UIs).

• Accessibility (TalkBack) at production depth