Zefr · 9 hours ago
Senior Machine Learning Engineer
Marina del Rey, CA
Full-time
Hybrid
Senior Level
$150K/yr - $200K/yr
5+ years expZefr is the leading global technology company enabling responsible marketing in walled garden social environments. They are seeking a Senior Machine Learning Engineer focused on ML Operations to design and build large-scale applications for processing social media data and implementing infrastructure for machine learning systems.
AdvertisingEnterprise SoftwareInternetMarketingVideoVideo Advertising
Responsibilities
Design and build large-scale applications and systems to acquire, process, and store multi-terabytes of social media data
Implement infrastructure to support machine learning systems at scale processing hundreds of millions of social media videos daily
Work with state of the art models, including large language models, to build sophisticated compound AI systems
Qualification
Required
Bachelor's or Master's degree in Computer Science or related field with 5+ years of professional experience in ML Engineering or MLOps
Strong foundation in mathematics and statistics
Deep expertise in ML model deployment, serving infrastructure, and production ML systems
Hands-on experience with transformer architectures (e.g., BERT, ViT) for natural language and vision tasks
Strong understanding of multimodal embedding techniques for integrating text, image, audio, and structured data
Experience with LLM models such as Gemini, GPT, Claude, Qwen, etc
Experience with ML experiment tracking, model versioning, and feature stores
Strong understanding of CI/CD principles applied to ML workflows
Experience optimizing model inference performance (ONNX, TensorRT, or similar)
Openness to new technologies and creative solutions
Preferred
Experience with ad tech and digital advertising ecosystem
Experience with multimodal LLM fine-tuning
Benefits
Flexible PTO
Medical, dental, and vision insurance with FSA options
Company-paid life insurance
Paid parental leave
401(k) with company match
Professional development opportunities
14 paid holidays off
Flexible hybrid work schedule
“Summer Fridays” (shorter work days on select Fridays during the summertime)
In-office lunches and lots of free food
Optional in-person and virtual events (we like to celebrate!)
Company
Zefr
Zefr is a technology company that uses artificial intelligence to deliver digital advertising services.
201-500 employees
H1B Sponsorship
Zefr has a track record of offering H1B sponsorships. Please note that this does not
guarantee sponsorship for this specific role. Below presents additional info for your
reference. (Data Powered by US Department of Labor)
Distribution of Different Job Fields Receiving Sponsorship
Represents job field similar to this job
Trends of Total Sponsorships
2025 (5)
2024 (3)
2023 (4)
2022 (10)
2021 (9)
2020 (2)
Funding
Current Stage
Late StageTotal Funding
$65.06MKey Investors
IVPU.S. Venture PartnersMK Capital
2016-03-09Series E· $5M
2014-02-26Series D· $30M
2012-08-15Series C· $18.5M
Leadership Team
Richard Raddon
Co-Founder, Co-CEO
Zach James
Co-Founder & Co-CEO
Recent News
2025-12-16
2025-12-11
Company data provided by crunchbase