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Machine Learning Performance Engineer

Pay
Pay not listed
Work setting
Not stated
Employment
Full-time — employment source
Employment type in the employer’s posting: Full-Time: Experienced
From the employer’s posting

What you’ll work on

Full posting
  • Optimise training and inference performance of ML models

  • Improve CUDA code and whole-system performance across storage, networking and GPUs

  • Check whether platform throughput is real useful work at the lowest level

From the employer’s posting
optimising the performance of our models – both training and inference
Part of this is improving straightforward CUDA, but the interesting part needs a whole-systems approach, including storage systems, networking and host- and GPU-level considerations
is all that throughput actually goodput?

What you’ll bring

All qualifications

Core experience

  • Experience with low-level systems programming and optimisation
  • Ability to debug a training run's performance end to end
  • Low-level GPU knowledge (PTX, SASS, warps, Tensor Cores, memory hierarchy)
  • Experience with CUDA profiling tools such as Nsight Systems and Nsight Compute
  • Knowledge of GPU libraries such as Triton, CUTLASS, cuDNN and cuBLAS
Qualification wording
an engineer with experience in low-level systems programming and optimisation
The experience and systems knowledge required to debug a training run’s performance end to end
Low-level GPU knowledge of PTX, SASS, warps, cooperative groups, Tensor Cores and the memory hierarchy
Debugging and optimisation experience using tools like CUDA GDB, NSight Systems, NSight Computesight-systems and nsight-compute
Library knowledge of Triton, CUTLASS, CUB, Thrust, cuDNN and cuBLAS

Posting record

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Open 6 monthsWe first saw this posting 204 days ago and it is still up. Roles open this long are often slow to fill or kept open to collect applications.

Status in our records
Live
First seen by us
Apr 14, 2026204 days ago
Recorded sightings
216
Last seen by us
Nov 4, 2026

These dates show when we found the posting. Check the employer’s website to confirm it is still accepting applications.

How this job compares

Time since we first saw it

Day 204

Up longer than most. Similar jobs usually come down between day 6 and day 68.

From 4,292 similar postings that came down. Coming down is not always a hire.

Jane Street is hiring

26 open jobs

Open jobs by the week we first saw them, last 12 weeks.

  • Hiring has slowed
  • Its jobs tend to stay up a long time
Hiring record

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Has Jane Street posted this job before?

Yes. We’ve followed 2 other Machine Learning Performance Engineer jobs there since April 2026. All 2 are still up.

  1. New YorkStill up after 204 days, first seen Apr 14
  2. LondonStill up after 204 days, first seen Apr 14
  3. This jobUp 204 days so far, first seen Apr 14

Job description

View original posting ↗

We are looking for an engineer with experience in low-level systems programming and optimisation to join our growing ML team. 

Machine learning is a critical pillar of Jane Street's global business. Our ever-evolving trading environment serves as a unique, rapid-feedback platform for ML experimentation, allowing us to incorporate new ideas with relatively little friction.

Your part here is optimising the performance of our models – both training and inference. We care about efficient large-scale training, low-latency inference in real-time systems and high-throughput inference in research. Part of this is improving straightforward CUDA, but the interesting part needs a whole-systems approach, including storage systems, networking and host- and GPU-level considerations. Zooming in, we also want to ensure our platform makes sense even at the lowest level – is all that throughput actually goodput? Does loading that vector from the L2 cache really take that long?

If you’ve never thought about a career in finance, you’re in good company. Many of us were in the same position before working here. If you have a curious mind and a passion for solving interesting problems, we have a feeling you’ll fit right in. 

There’s no fixed set of skills, but here are some of the things we’re looking for:

  • An understanding of modern ML techniques and toolsets
  • The experience and systems knowledge required to debug a training run’s performance end to end
  • Low-level GPU knowledge of PTX, SASS, warps, cooperative groups, Tensor Cores and the memory hierarchy
  • Debugging and optimisation experience using tools like CUDA GDB, NSight Systems, NSight Computesight-systems and nsight-compute
  • Library knowledge of Triton, CUTLASS, CUB, Thrust, cuDNN and cuBLAS
  • Intuition about the latency and throughput characteristics of CUDA graph launch, tensor core arithmetic, warp-level synchronization and asynchronous memory loads
  • Background in Infiniband, RoCE, GPUDirect, PXN, rail optimisation and NVLink, and how to use these networking technologies to link up GPU clusters
  • An understanding of the collective algorithms supporting distributed GPU training in NCCL or MPI
  • An inventive approach and the willingness to ask hard questions about whether we're taking the right approaches and using the right tools
  • Fluent in English

 

If you're a recruiting agency and want to partner with us, please reach out to agency-partnerships@janestreet.com.

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Location & working pattern

Hong Kong, Hong Kong

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