Perplexity

Perplexity

Posted via Ashby

Member of Technical Staff (AI Inference Engineer)

Posted Aug 5, 2026

Role at a glance

Salary
Not Disclosed
Location
London
Work arrangement
On-site
Employment
Full-time
Experience
3+ years of professional software engineering experience with meaningful work on ML inference or high-performance systems.

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Role Summary

AI-generated

The AI Inference Engineer will work on the inference engine behind Perplexity queries, supporting multiple model architectures at scale across Rust, Python, CUDA, and CuTe DSL. The role focuses on improving serving performance, portability, reliability, and observability under tight latency and cost budgets.

What You'll Do

  • Support transformer-based retrieval, text-generation, and multimodal models across weight loading, request scheduling, KV-cache...
  • Port in-house CUDA kernels to NVIDIA's CuTe DSL for GB200 and future Vera Rubin rack portability.
  • Develop the internal Rust-based inference server.
  • Profile and fix bottlenecks from network ingress through continuous batching and GPU kernel interleaving.
  • Build dashboards, alerts, and automated remediation, and respond to and learn from production incidents.

Generated from the employer's posting. Verify important details before applying.

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Qualifications

Deep experience with GPU programming and performance work; understanding of modern LLM architectures and production inference; experience building and operating production distributed systems under real load; familiarity with at least one deep learning framework; understanding of GPU architectures and common LLM architectures and inference optimization techniques.

Required

  • GPU programming and performance work with CUDA, Triton, CUTLASS, or similar
  • Modern LLM architectures and production inference
  • Production distributed systems under real load
  • Rust, Python, and CUDA/CuTeDSL
  • At least one deep learning framework: PyTorch, JAX, or TensorFlow
  • GPU architectures, including memory hierarchy, warp scheduling, and tensor cores
  • Inference optimization techniques, including quantization, speculative decoding, and prefill-decode disaggregation

Preferred

  • PyTorch internals
  • torch.compile
  • Custom operators
  • NCCL
  • NVLink
  • InfiniBand
  • RDMA libraries
  • Model/tensor parallelism

Original job description

Content provided by the employer

We are looking for an AI Inference Engineer to join our growing team. We build and run the inference engine behind every Perplexity query and deploy dozens of model architectures at scale with tight latency and cost budgets. Our stack is Rust, Python, CUDA, and CuTe DSL.

Responsibilities:

  • New models support. Support transformer-based retrieval, text-generation, and multimodal models in our inference infrastructure, from weight loading, request scheduling and KV-cache management to support in API Gateway.

  • GPU kernels migration to CuTe DSL. Port our in-house CUDA kernels to NVIDIA's CuTe DSL so they run on GB200 today and are portable to Vera Rubin racks tomorrow.

  • Rust-native serving runtime. Develop our internal Rust-based inference server to solve all Python pains and keep up with rapidly growing traffic.

  • Performance optimisation. Profile and fix bottlenecks from network ingress through continuous batching and GPU kernels interleaving.

  • Reliability and observability. Build dashboards, alerts, and automated remediation so we catch regressions before users do. Respond to and learn from production incidents.

Who we're looking for:

  • Deep experience with GPU programming and performance work (CUDA, Triton, CUTLASS, or similar). Any other deep systems programming experience is a plus.

  • You understand modern LLM architectures and are able to bring them up reliably in a production environment.

  • You've built and operated production distributed systems under real load - ideally performance-critical ones.

  • Comfortable working across languages and layers: Rust for the serving runtime, Python for model code, CUDA/CuteDSL for kernels.

  • You own problems end-to-end. You can read a research paper on Monday, write a kernel on Wednesday, and debug a production incident on Friday.

  • Self-directed. You do well in fast-moving environments where the path forward isn't laid out for you.

Nice-to-have:

  • 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.

Qualifications:

  • 3+ years of professional software engineering experience with meaningful work on ML inference or high-performance systems.

  • 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).

Final offer amounts are determined by multiple factors including experience and expertise.

Equity: In addition to the base salary, equity may be part of the total compensation package.

Perplexity

About the company

Perplexity

Startup

Perplexity is an innovative technology company that specializes in developing advanced artificial intelligence solutions aimed at enhancing human-computer interaction. With a focus on natural language processing and machine learning, Perplexity empowers users to access information and insights more intuitively and efficiently. The company is dedicated to creating tools that simplify complex data and foster informed decision-making, thereby transforming the way individuals and organizations engage with knowledge. Through its commitment to excellence and user-centric design, Perplexity is shaping the future of information retrieval and analysis.