Perplexity
Member of Technical Staff (AI Inference Engineer)
London. Posted 7 months ago
The role
This person will build and run the inference engine behind Perplexity queries. They will deploy model architectures at scale using Rust, Python, CUDA, and CuTe DSL.
What you will do
- Support transformer-based retrieval, text-generation, and multimodal models in inference infrastructure
- Port in-house CUDA kernels to NVIDIA's CuTe DSL
- Develop internal Rust-based inference server
- Profile and fix bottlenecks from network ingress through continuous batching and GPU kernels interleaving
- Build dashboards, alerts, and automated remediation
- Respond to and learn from production incidents
Required qualifications
- 3+ years of professional software engineering experience with meaningful work on ML inference or high-performance systems
- Deep experience with GPU programming and performance work (CUDA, Triton, CUTLASS, or similar)
- Understand modern LLM architectures and are able to bring them up reliably in a production environment
- Built and operated production distributed systems under real load
- Comfortable working across languages and layers: Rust, Python, CUDA/CuteDSL
- Familiarity with at least one deep learning framework (PyTorch, JAX, TensorFlow)
- Understanding of GPU architectures (memory hierarchy, warp scheduling, tensor cores)
- Understanding of common LLM architectures and inference optimization techniques (e.g. quantization, speculative decoding, prefill-decode disaggregation)
Nice to have
- Any other deep systems programming experience
- ML compilers and framework internals: PyTorch internals, torch.compile, custom operators
- Distributed GPU communication: NCCL, NVLink, InfiniBand, RDMA libraries, model/tensor parallelism
- Low-precision inference: INT8/FP8/FP4 quantization, mixed-precision serving
- Profiling and debugging tools: Nsight Compute/Systems, CUDA-GDB, PTX/SASS analysis
- Container orchestration: Kubernetes, GPU scheduling, autoscaling inference workloads
About the company
Perplexity builds and runs the inference engine behind every Perplexity query and deploys dozens of model architectures at scale.