Senior iOS Engineer

Ola Chat; Kuala Lumpur; Hybrid; MYR 180,000 - 240,000; Full time

Job summary

Ola Chat Pte Ltd. is seeking a Senior Mobile Performance Engineer to optimize a Flutter and native iOS hybrid app for global markets.

You will tackle startup time, frame rates, memory footprint, and energy usage on older devices, across the shared Flutter layer and native iOS. Collaboration with cross-functional teams is essential.

Qualifications

• 5+ years of mobile development experience with native iOS and Flutter performance optimization.
• Strong proficiency in Swift/Objective-C and Dart, ARC, RunLoop, GCD, and iOS lifecycle.
• Deep understanding of Flutter widget tree, rendering, and Platform Channel mechanics.
• Experience with profiling tools (Instruments, Memory Graph,DevTools) for bottleneck diagnosis.
• Proven track record in optimizing performance and reducing regressions across devices.

Responsibilities

• Lead performance optimization for Flutter and iOS hybrid app, improving startup time, frame rates, memory efficiency, and energy use.
• Diagnose and fix main thread blocking, frame drops, memory leaks, and crashes on legacy devices.
• Optimize Flutter rendering, widget rebuilds, image decoding, and asynchronous tasks.
• Streamline integration between Flutter and native iOS pages, Platform Views, and 3rd-party SDKs.
• Establish production performance metrics and regression testing across devices/OS versions.
• Collaborate with Android, QA, and product teams to reduce performance regressions.

Skills

Mobile development

Native iOS

Flutter development

Performance optimization

Swift/Obj-C

Dart

iOS internals

Profiling & diagnostics

Cross-functional collaboration

Tools

Xcode Instruments

Flutter DevTools

Xcode Memory Graph

Job description

We operate a mature mobile application targeting global markets, built primarily on a Flutter + native iOS/Android hybrid architecture.

Our current technical focus is continuously enhancing application performance and stability, with a strong emphasis on delivering a smooth experience on older, low-memory iPhones under complex usage scenarios. In this role, you will work across both the shared Flutter layer and the native iOS layer to tackle real-world challenges related to UI jank, memory footprint, startup time, battery consumption, and hybrid architecture interactions.

Key Responsibilities

• Performance Governance: Lead performance optimization for our Flutter & iOS hybrid app, continuously improving startup time, frame rates, memory efficiency, energy consumption, and overall stability.
• Deep Troubleshooting: Diagnose and resolve main thread blocking, frame drops, memory leaks, abnormal memory growth, system memory terminations (Jetsam), and crashes, prioritizing UX improvements for legacy devices.
• Flutter Rendering Optimization: Optimize Flutter widget building, layout, and rendering pipelines—resolving issues caused by unnecessary rebuilds, image decoding/caching, long scrollable lists, animations, and asynchronous tasks.
• Hybrid Integration & Interop: Streamline integration between Flutter and native iOS pages, Platform Views, platform channel communications, and 3rd-party SDKs, addressing thread scheduling, object retention, and resource cleanup.
• Metrics & Regression Control: Establish production performance metrics, device/OS version stratified analysis, and regression testing mechanisms, validating optimization gains on physical devices.
• Cross-Functional Collaboration: Partner with Android, QA, and product engineering teams to drive shared Flutter layer optimizations, manage platform-specific differences, and lower performance regression risks.

Key Requirements

• Experience: 5+ years of mobile development experience with a strong foundation in native iOS, alongside hands-on production experience with Flutter development and performance optimization.
• Core Tech Stack: Proficient in Swift/Objective-C and Dart, with a deep understanding of ARC, RunLoop, GCD, thread synchronization, rendering pipelines, and the iOS application lifecycle.
• Flutter Internal Mechanics: Solid grasp of the Widget, Element, and RenderObject hierarchy, UI/Raster threads, Event Loops, Isolates, and Platform Channel mechanics.
• Profiling & Diagnostics: Proficient with Xcode Instruments (Time Profiler, Allocations, Leaks), Xcode Memory Graph, and Flutter DevTools for precise performance bottleneck identification.
• iOS System Architecture: Deep understanding of iOS memory pressure, background execution, and system termination mechanisms, with the ability to combine device logs and production telemetry for root-cause analysis.
• Track Record: Proven history of successful production performance optimizations, with the ability to clearly articulate problem contexts, diagnostic processes, implemented solutions, quantified gains, and regression validation protocols.
• Cross-Layer Debugging: Strong capability to determine whether bottlenecks originate from Dart, Flutter rendering, native iOS modules, 3rd-party SDKs, or OS resource limits.
• Execution & Ownership: Ability to independently drive optimization initiatives in a mature codebase while balancing technical ROI, compatibility, and release risks.

Preferred Qualifications (Nice to Have)

• Experience with performance governance for legacy iPhone models, low-memory devices, and multi-version iOS environments.
• Hands-on optimization experience in high-demand scenarios such as audio/video, real-time communication (RTC), complex animations, or high-frequency image rendering.
• Familiarity with C/C++, Flutter Engine internals, Impeller, Metal, or graphics rendering technologies.
• Experience with MetricKit, APM/production jank monitoring systems, performance metrics frameworks, or automated performance testing pipelines.

Remarks: This role is currently on a hybrid arrangement. However, employees may be required to return to the office on a full on-site basis in the future, subject to company policy.