Deep, hands-on experience building native iOS and/or Android — you understand the platform, not just a framework on top of it
Experience with a cross-platform / shared business-logic layer. We build ours in Rust + UniFFI; direct Rust-on-mobile experience is a strong plus, but experience with any shared-logic approach — KMP, Flutter, or React Native — transfers well and is valued
Fluent in at least one of: Swift / Kotlin / Rust / Objective-C / Java / JavaScript, with strong CS fundamentals
Architecture experience with large-scale mobile apps — you've applied maintainable design patterns and own solutions from requirements through to production
Depth in at least one layer of the messaging stack, and the ability to work across both — whether your strength is chat/feature-level UX or real-time / networking internals: WebSocket / long-connection, and/or offline push delivery across overseas + China channels (APNs, FCM, and China vendor push). Bonus if you have the depth to reason about a messaging engine from the ground up, not just consume one
Strong mobile performance chops (memory, battery, concurrency, weak-network)
You apply AI deeply in your own engineering — not just code generation. You've built, or are driven to build, automated development workflows and harnesses that make delivery both faster and more reliable. Solid grasp of LLM fundamentals, prompt engineering, RAG, and agent concepts, with hands-on experience taking an AI pipeline from scratch to shipped — and you're excited to build user-facing conversational / agent-chat experiences too
Comfortable with ambiguity and high scale — you've debugged problems that only appear under real production load
Signals we value: you naturally raise the standard of teams you join, mentor without being asked, and can grow into a technical anchor for the group
Built or maintained an IM / chat product, or an SDK consumed by other teams
Experience with mini-program or dynamic/hot-update frameworks
Crypto trading / Web3 experience