Senior Software Engineer, C/C++ SDK Performance Optimization

Description

About this team
We own the Effect SDK powering TikTok's camera and creation experience — the system behind every filter, AR effect, and visual effect used by hundreds of millions of creators every day. This role sits at the business architecture layer of a self-developed rendering engine, partnering closely with rendering, algorithm, and camera pipeline teams to deliver smooth, low-power effect experiences across a massive range of mobile devices.

Responsibilities
- Drive end-to-end experience optimization of the effect pipeline during shooting — diagnose and resolve frame drops, jank, thermal throttling, and power consumption issues on real user devices.
- Profile the full camera→effect→render→encode pipeline; identify bottlenecks across CPU, GPU, memory, and thread scheduling, and land measurable improvements.
- Collaborate with the rendering engine team to understand and leverage low-level capabilities, and with the on-device algorithm team to co-optimize model integration and execution.
- Build and evolve the business architecture of the Effect SDK (Native, cross-platform for iOS & Android), turning product requirements into robust, maintainable modules.
- Localize and fix technical problems and bugs reported from production, with a strong ownership mindset.
- Learn new techniques quickly, communicate clearly, and collaborate well across teams.

Requirements

Minimum Qualifications
- B.S. or M.S. in Computer Science with 4+ years of relevant experience.
- Proficient in C/C++;
- Strong interest in performance on mobile devices — you enjoy digging into profilers and chasing down the last millisecond.
- Familiar with iOS and/or Android development, and has experience in video and image processing related applications on mobile phones

Preferred Qualifications
- Hands-on experience with mobile profiling tools (Xcode Instruments, Perfetto / Systrace, Android GPU Inspector, RenderDoc, etc.).
- Experience optimizing frame rate stability, memory footprint, thermal, or battery consumption in a consumer-scale mobile app.
- Familiarity with camera pipelines (AVFoundation / Camera2 / CameraX) or real-time video processing.
- Experience with AR, game engine, or real-time graphics development.
- Experience integrating on-device inference frameworks (CoreML, TNN, MNN, NCNN, TFLite) and optimizing their runtime cost.
- Basic understanding of graphics rendering APIs (OpenGL ES / Metal / Vulkan); shader programming experience is a plus