Lead Software Engineer, iOS, Zalo

Rolled out in 2012, Zalo has proved itself as the leading instant messaging app in Vietnam with more than 70 million monthly active users. We develop a messaging application that provides fast, stable, convenient, and private connection for users anytime, anywhere.What you will do:Define and drive the iOS platform strategy: own architectural decisions across modularization, dependency management, build systems, and shared frameworks used at scale across teams;Build and evolve core platform foundations: design, develop, and maintain internal SDKs and reusable libraries powering all iOS products;Lead modular architecture transformation: shape a scalable, maintainable codebase by defining module boundaries, enforcing dependency rules, and enabling team autonomy;Own the iOS build & release ecosystem: optimize build performance, manage CI/CD pipelines, code signing, and release automation to ensure fast and reliable delivery;Ensure platform reliability and performance excellence: drive initiatives across app launch time, memory footprint, crash rate, and system stability;Continuously modernize the platform: lead iOS, Xcode, and Swift migrations while proactively addressing toolchain and compatibility challenges;Set and enforce engineering standards: establish best practices in architecture, code quality, security, and development workflows across teams;Elevate developer experience (DevEx): build internal tooling (templates, code generators, linters, documentation) to maximize engineering productivity;Act as a technical leader and mentor: guide engineers on system design, iOS internals, concurrency, and debugging in production environments;Collaborate cross-functionally: serve as the key technical bridge between iOS, Backend, QA, DevOps, Security, and Product teams;Explore and adopt emerging technologies: evaluate new Apple frameworks and define adoption strategies aligned with business needs.What you will need:5+ years of iOS development experience, with deep expertise in both Objective-C and Swift, including large-scale, production-grade systems;2+ years in a technical leadership role (Tech Lead, Senior / Lead Developer) on a large iOS codebase;Strong understanding of iOS internals: app lifecycle, memory management, concurrency, and runtime behavior;Advanced knowledge of concurrency models (Grand Central Dispatch, Swift Concurrency) and thread safety;Hands-on experience with modularization and large-scale build systems;Deep expertise in modern iOS architecture patterns (MVVM, Clean Architecture) with the ability to evaluate trade-offs;Strong background in performance optimization: profiling, debugging, and improving app performance at scale;Solid understanding of iOS security and privacy standards, including secure data storage and network communication;Proficiency in CI/CD pipelines, code signing, provisioning, and automated release processes;Strong experience with UIKit (and familiarity with modern UI frameworks is a plus);Excellent communication skills: able to write clear technical documents, lead design discussions, and influence stakeholders;Passion for mentorship and engineering excellence, with a track record of growing high-performing teams;High ownership mindset, pragmatic decision-making, and a strong focus on impact.