Contact person: Business Client

Phone:Show

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Location: 中国, China

Budget: Recommended by industry experts

Time to start: As soon as possible

Project description:
"My Signal-derived messaging server is already live; what I now need is a developer who can take both the iOS and Android codebases to production-ready quality. The work centers on deep client-side refinement rather than server logic, so you should be completely at home inside Xcode and Android Studio, comfortable working with Swift (or Objective-C) and Kotlin/Java, and ready to navigate Signal’s source tree and APIs.

End-to-end encryption is non-negotiable. You must understand and have actually implemented the Double Ratchet algorithm, X3DH key agreement and the accompanying PreKeys flow. I’ll expect you to keep the cryptographic handshake, session management and message sealing intact while you add or overhaul features.

For instant-messaging behaviour, the three areas that need immediate attention are:
• Message delivery and read receipts
• Group chat functionality
• Media and file sharing (images, video, documents)

Your tasks will include UI tuning, adding missing features, hunting down performance bottlenecks and eliminating crash-level bugs. Familiarity with Telegram’s (tg) architecture is a plus because I often benchmark usability against it.

Deliverables: updated iOS and Android apps that pass TestFlight/Play-Store internal testing, exchange encrypted messages flawlessly with the existing server, and provide the IM features above without regression. If you have shipped secure chat apps before, let’s talk—I’m ready to start as soon as you are." (client-provided description)