Unity • Rendering • Frame Pacing • XR Optimization
I build deterministic performance systems for real-time applications — focusing on stable frame delivery, GPU/CPU bottleneck isolation, and reproducible profiling workflows.
- Diagnose CPU vs GPU bottlenecks using profiler-backed experiments
- Design controlled stress environments to reproduce performance issues
- Optimize rendering pipelines for mobile and XR constraints
- Maintain stable frame budgets (11ms / 16.6ms) under load
- Build telemetry-driven systems to monitor runtime health
The goal is simple: consistent frame delivery under real-world stress — not just high FPS in ideal conditions.
Performance problems are not random. They are measurable, reproducible, and isolatable.
My workflow:
- Establish baseline → apply controlled stress → measure delta
- Separate CPU vs GPU cost using profiler evidence
- Eliminate variance before applying optimizations
- Validate improvements with repeatable scenarios
If it cannot be reproduced, it cannot be fixed reliably.
Deterministic stress framework for analyzing rendering cost in XR.
Focus areas:
- Stereo rendering overhead
- Overdraw amplification (200+ transparent layers)
- MSAA cost scaling
- Fragment workload vs submission cost
Key finding:
- Single rendering factor produced +7ms GPU cost under stereo load while CPU remained stable → clear GPU-bound scenario
🔗 https://github.com/JamesDeRaja/XRPerformanceLab
Performance breakdown of Unity UI masking under layered transparency.
Focus areas:
- Mask pass cost in UI pipelines
- Overdraw amplification in stacked elements
- Canvas rebuild CPU impact
- Tradeoffs between visual fidelity and performance
Result:
- Clear identification of GPU-heavy UI scenarios caused by layered transparency and masking
🔗 https://github.com/JamesDeRaja/SoftMaskPro-Performance-Study
Comparison of update architectures under scale.
Variants:
- A — Per-object Update (baseline)
- B — Prefab-based Update
- C — Central Manager
- D — ECS (DOTS + Burst)
Focus areas:
- CPU scaling to 10,000+ entities
- GC elimination
- Update cost distribution
- Deterministic simulation control
Outcome:
- Measurable reduction in CPU overhead and improved scalability with ECS-based systems
🔗 https://github.com/JamesDeRaja/ECS-Performance-Improvement
Performance is a systems problem.
- Define budgets in milliseconds, not FPS
- Measure before optimizing
- Remove non-determinism
- Validate under stress, not ideal conditions
Architecture drives performance more than micro-optimizations.
- 13+ years in real-time systems and Unity development
- Worked with publishers: Voodoo, Lion Studios, Supersonic
- Built and optimized systems for hundreds of live game features
- Improved retention and performance metrics through optimization-driven design
🌐 https://james.alphaden.club 🔗 https://www.linkedin.com/in/james-de-raja/

