Senior Software Engineer, iOS, Storage Management
Full-time
Zalo is Vietnam’s leading messaging platform with 70M+ monthly active users. Join the team building our new paid cloud storage service for chat data - designing backup, restore, sync, and device-transfer systems at massive scale, with performance and privacy as non-negotiables.
🤖 What you will do
- Design and build core cloud storage features: cloud backup & restore, local storage management, cross-device transfer, and device–cloud sync - owning a feature area end-to-end;
- Solve hard problems at scale: multi-GB datasets, resumable transfers on unreliable networks, encryption, deduplication, conflict-free sync;
- Optimize app performance: memory, energy, I/O, and smooth UX during heavy background work;
- Use AI coding agents as a core part of your workflow while owning the quality of everything you ship;
- Collaborate with Product, UI/UX, backend, and QC.
👾 What you will need
- 3+ years of software engineering experience with iOS production experience; BSc/MSc in CS/IT or equivalent ability;
- Very strong CS fundamentals: threading & concurrency (GCD, Swift Concurrency), memory (heap/stack, leaks, profiling), networking (sockets, HTTP/TLS), app performance;
- Strong problem solving and practical system design — clear reasoning about trade-offs and failure modes;
- Good iOS domain knowledge: Swift (primary), UIKit/SwiftUI, background execution, iOS security model; Objective-C a plus;
- Storage & sync depth in several of: SQLite (GRDB/WCDB/Core Data), migrations, offline-first sync & conflict resolution, resumable transfer, encryption at rest, P2P device transfer;
- Good software architecture: MVVM, Clean Architecture, DI; solid unit-testing habits (XCTest, CI/CD);
- AI-adoption mindset: hands-on with AI coding tools/agents (Claude Code, Codex,…); able to direct, verify, and optimize AI-assisted workflows;
- Strong ownership and delivery: self-lead a feature area, communicate clearly, ship reliably.
Nice to have: - Large-scale consumer apps (millions of DAU); chat/messaging engineering (WebSocket, Protobuf, media pipelines); cross-platform schema parity with Android.
