ML Foundations and GPU Acceleration
You will need to connect ML concepts with GPU execution realities. Interviewers will test whether you can choose algorithms that map well to GPU architectures, understand memory bandwidth vs. compute bounds, and design training/inference to achieve near-roofline performance.
Be ready to go over:
- Algorithm–hardware alignment: When to use gradient boosted trees, k-means, or ANN/vector search on GPUs; batching, mixed precision, and memory coalescing.
- Deep learning training fundamentals: Optimizers, schedulers, loss surfaces, regularization, and how they interact with DDP/FSDP and NCCL.
- Performance metrics: Throughput, latency, utilization, strong/weak scaling, Amdahl’s law, and reproducible benchmarks.
- Advanced concepts (less common): Kernel fusion, Tensor Cores, CUDA streams/graphs, quantization and sparsity, sim-to-real transfer, and VLA (Vision‑Language‑Action) models.
Example questions or scenarios:
- “Design a reproducible benchmark to compare a CPU vs. multi‑GPU GBDT training pipeline. What metrics and datasets do you choose, and how do you ensure fair comparisons?”
- “Your ANN/vector search recall is high but latency is too slow on multi-GPU. Where are the likely bottlenecks and what optimizations do you try first?”
- “Explain how mixed precision interacts with convergence and numerical stability for a large model. How do you detect and mitigate issues?”
Coding, Algorithms, and Low-Level Performance
You will write or reason through code in Python and C++, sometimes with CUDA concepts. Clarity, correctness, and performance‑aware design matter. Expect classic algorithms combined with GPU-aware thinking.
Be ready to go over:
- Data structures and algorithms: Trees, heaps, graphs, search/approximate search, streaming algorithms, and memory layouts.
- C++/CUDA fluency: RAII, templates, concurrency, device/host transfers, kernel launches, occupancy, and profiling.
- Numerical stability and precision: Loss scaling, accumulation strategies, deterministic behaviors.
- Advanced concepts (less common): CUDA cooperative groups, warp-level primitives, custom kernels for data augmentation or post-processing.
Example questions or scenarios:
- “Implement a streaming top‑K in Python and discuss how you’d re-architect for multi‑GPU.”
- “Given a kernel with poor occupancy, walk through your profiling and optimization steps.”
- “Refactor a data pipeline to minimize host–device transfers and improve end‑to‑end latency.”
ML Systems Design and Distributed Training
System design interviews focus on scalable training/inference, data orchestration, and observability. You’ll define interfaces, failure modes, and performance SLAs.
Be ready to go over:
- Distributed training: DDP/FSDP, tensor/pipeline parallelism, sharding strategies, elastic training, and checkpointing.
- Data pipelines: Shuffling, caching, prefetching, and synthetic data generation (e.g., for robotics).
- Inference stacks: Model packaging, quantization, batching, and real-time latency constraints (graphics, robotics).
- Advanced concepts (less common): NCCL topology considerations, multi-tenant cluster fairness, and multi-node failure recovery.
Example questions or scenarios:
- “Design a system to train a foundation model with FSDP across 64 GPUs. How do you optimize communication and memory use?”
- “Propose an inference architecture for real-time video enhancement with strict latency targets.”
- “Outline a sim-to-real pipeline for humanoid loco‑manipulation with ongoing domain adaptation.”
MLOps, Reproducibility, and Benchmarking
NVIDIA teams value production discipline: versioning, CI/CD, and automated performance tests across GPU SKUs and scales.
Be ready to go over:
- MLOps toolchain: Docker/NGC, SLURM/Kubernetes, artifact registries, and GitHub Actions.
- Testing strategy: Unit/functional/perf tests; deterministic seeds; reproducible environment manifests.
- Observability: Metrics/logging/tracing for training and inference; failure triage and rollback plans.
- Advanced concepts (less common): Heterogeneous scheduling, cost/perf modeling, cluster capacity planning, MLPerf‑style benchmarking.
Example questions or scenarios:
- “Design a performance test harness that validates training throughput across A100, H100, and multi-node scales.”
- “Your training run diverges intermittently on larger clusters. How do you debug and stabilize?”
- “How do you structure CI to gate releases of an accelerated ML library (e.g., cuML) with reproducible perf thresholds?”