Senior Software Engineer, Zalo

As a member of the Platform Team, your primary responsibility is to develop and maintain core instant systems (real-time/instant experiences) with a strong emphasis on deep technical know-how and algorithmic/problem-solving capability.

This role is open to candidates with a strong mobile background in either iOS or Android

What you will do

• Design, develop, and optimize high-performance mobile platform components and core functionalities (iOS/Android), with minimal reliance on third-party libraries;
• Tackle complex technical challenges using strong algorithmic and analytical skills, ensuring performance, reliability, and scalability at platform level;
• Continuously explore and integrate new technologies, frameworks, and best practices to enhance Zalo’s instant platform efficiency and developer productivity;
• Collaborate with cross-functional teams (Product, Design, Backend, QA, etc.) to implement and refine product features with a platform-first mindset (reusable, stable, long-term maintainable).

What you need

• 2+ years of software development experience with strong exposure to core system architecture and platform-level thinking;
• Strong proficiency in either Android (Java/Kotlin, Android SDK, app/framework internals, tooling) or iOS (Swift/Objective-C, iOS SDK, runtime fundamentals, tooling);
• Solid knowledge of algorithms, data structures, and OOP;
• Hands-on experience with memory management and multithreading/concurrency: Android: JVM/ART memory behavior, threading, concurrency primitives, iOS: ARC, retain cycles, GCD/OperationQueue/Swift Concurrency;
• Experience in performance optimization (profiling, tracing, CPU/memory/battery/network optimization) is highly desirable;
• Proactive, open-minded, strong sense of ownership, and eager to learn and grow;

Nice to have

• C/C++ knowledge (useful for low-level system work, performance-critical modules, native integrations);
• Familiarity with the core functionality of cross-platform frameworks such as Flutter or React Native (integration patterns, performance trade-offs);
• Strong research skills with the ability to quickly adapt to technologies beyond mobile (e.g., networking/real-time systems, runtime optimization, platform tooling).