# Senior Machine Learning Engineer, ML Efficiency

**Company:** [Reddit](https://hotfix.jobs/companies/reddit)
**Location:** Remote
**Role:** ML Engineering
**Salary:** $217k – $303k/yr
**Experience:** 5+ years
**Skills:** ml systems, PyTorch, Distributed Training, model compression, quantization, pruning, distillation, gpu training, profiling, benchmarking, Observability, kernel optimization, runtime optimization
**Posted:** 2026-07-24

> Senior ML engineer focused on improving training and inference efficiency for Reddit's Ads ML models. Own optimization initiatives, diagnose production bottlenecks, build reusable tooling and primitives, and mentor others on measurable efficiency and launch-safety wins.

## Job Description

## What you’ll do

- Independently own high-value optimization initiatives across training, inference, or launch-readiness for important Ads ML workloads.
- Diagnose bottlenecks in real production systems using profiling, benchmarking, and observability rather than intuition-first debugging.
- Build performance tooling, optimization playbooks, observability hooks, guardrails, or efficiency primitives that help more than one team or workload over time.
- Improve launch-safety and efficiency readiness by contributing to load testing, fallback readiness, latency and cost visibility, and operational confidence for heavy models.
- Work with model owners and platform teams to land pragmatic fixes while helping the team gradually standardize repeated solutions.
- Contribute to the team’s technical direction by surfacing patterns, tradeoffs, and opportunities for reuse or automation.
- Mentor less-experienced engineers through code, debugging, measurement rigor, and strong execution habits.

## What we’re looking for

- Deep ML systems experience close to real production models and workloads, not just generic infra exposure.
- Direct hands-on experience improving training or serving efficiency with measurable outcomes.
- Strong technical judgment across model-level, runtime-level, and infrastructure-level optimization choices.
- Ability to own complex projects end to end and collaborate effectively across team boundaries.
- Good customer and platform instincts: can solve concrete bottlenecks while keeping maintainability, adoption, and future reuse in mind.
- Strong communication: able to explain tradeoffs clearly to engineers and partner teams.

## Nice-to-have

- Experience with GPU training or serving migrations.
- Experience with PyTorch, distributed training frameworks, or kernel/runtime optimization.
- Experience building launch certification, efficiency benchmarking, or cost observability systems.
- Experience in organizations where platform and applied modeling responsibilities are split across multiple teams.
- Experience with model compression or deployment optimizations such as quantization, pruning, distillation, or checkpoint optimization.

## Similar roles

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- [Senior Machine Learning Engineer, Ads Content Understanding](https://hotfix.jobs/jobs/ada32c3a-a5d5-401a-806b-70910c5055b4) - Reddit - Remote - $217k – $303k/yr
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- [Senior Machine Learning Engineer, Ads](https://hotfix.jobs/jobs/38a90e06-7152-474a-aaf0-bd106f198aee) - Reddit - Remote - $217k – $303k/yr
- [Senior Machine Learning Systems Engineer](https://hotfix.jobs/jobs/c8c6d8a6-2830-4989-9563-d1b4f373c6b0) - Reddit - Remote - $217k – $303k/yr

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