Staff Machine Learning Engineer (AI Security)

Location: Remote - United States

Base salary: $230,000–$322,000 USD per year, plus potential equity and commission depending on the position offered.

Company

Reddit is a large community platform whose AI Security team builds protections across products, engineering systems, AI platforms, and operational infrastructure.

What you will do

• Develop, fine-tune, evaluate, and deploy pretrained models and lightweight classifiers for AI security problems.
• Build reproducible training and evaluation pipelines on the ML platform, improving inference performance, resource efficiency, and operational reliability.
• Set the modeling vision and multi-quarter roadmap while defining architectures and requirements with cross-functional partners.
• Analyze model performance, adversarial robustness, false positives, latency, throughput, reliability, and cost to define launch criteria.
• Own training-data quality and the production model lifecycle, including monitoring, retraining, safe rollouts, and rollbacks.
• Mentor engineers, lead technical reviews, and establish responsible ML development practices.

Requirements

• 8+ years of experience developing machine learning models, including hands-on training experience and production impact.
• Strong Python and software engineering skills with deep learning frameworks such as TensorFlow, PyTorch, or Hugging Face Transformers.
• Understanding of neural network architectures, optimization, data preprocessing, tokenization, embeddings, language modeling, and model calibration.
• Experience with scalable data pipelines and distributed training frameworks such as Ray Train or PyTorch Distributed.
• Strong experimental design and evaluation skills, including holdouts, ablation studies, adversarial testing, and error analysis.
• Excellent written and verbal communication skills for explaining model behavior, security risks, uncertainty, and tradeoffs.

Nice to have

• Experience applying ML to security, trust and safety, fraud, privacy, or other adversarial domains.
• Experience with adversarial training, model distillation, active learning, or synthetic-data generation.

Culture & Benefits

• Healthcare benefits and income replacement programs.
• 401(k) with employer match.
• Global benefit programs supporting workspace, professional development, and caregiving.
• Family planning support, gender-affirming care, and mental health and coaching benefits.
• Flexible vacation, paid volunteer time off, and paid parental leave.

Hiring process

• In select roles and locations, interviews may be recorded, transcribed, and summarized by AI; candidates can opt out before scheduled interviews.
• Personal information may be collected during interviews to evaluate employment or independent contractor applications.