Senior ML Data Scientist: Real-Time Image Gen & Safety

Hapiko; New York (NY); On-site; USD 150,000 - 250,000; Full time

Job summary

Hapiko in Brooklyn, NY, is building the future of play with Stickerbox, an AI-powered voice-to-sticker printer for kids. We’re seeking a Data Scientist to own data quality, evaluation, and ML optimization across the pipeline, from data to deployment.

You’ll train models, refine safety guardrails, and work with a small team to ship reliable, kid-friendly AI experiences on real hardware. This is an on-site role in NYC with equity and benefits.

Qualifications

• 5+ years in data science or applied ML.
• Experience optimizing production ML systems.
• Strong statistical and analytical skills.
• Familiarity with LLMs and image generation models.
• Python proficiency; comfortable with PyTorch.
• Experience building evaluation frameworks.
• Track record of improving ML system performance through data and experimentation.

Responsibilities

• Build and curate large-scale image datasets for training custom models.
• Design annotation pipelines and data quality processes.
• Analyze training runs and model outputs to guide iteration.
• Work with our team to define what to train on and how to evaluate it.
• Optimize transcription pipeline for accuracy and latency.
• Improve image generation quality, prompt adherence, and consistency.
• Identify bottlenecks and failure modes across the pipeline.
• Run experiments and A/B tests to measure improvements.
• Refine content safety systems for child-appropriate outputs.
• Build evaluation frameworks to measure model performance at scale.
• Define metrics that correlate with user satisfaction.
• Develop automated evaluation pipelines (LLM-as-judge, CLIP scores, human eval).
• Track experiments and communicate findings to the team.
• Build prompt templates and guidelines for different use cases.

Skills

Data science

Applied ML

Production ML

Statistics

Python

PyTorch

Evaluation frameworks

Experimentation

Tools

Label Studio

Scale AI

Job description

Hapiko in Brooklyn, NY, is building the future of play with Stickerbox, an AI-powered voice-to-sticker printer for kids. We’re seeking a Data Scientist to own data quality, evaluation, and ML optimization across the pipeline, from data to deployment.

You’ll train models, refine safety guardrails, and work with a small team to ship reliable, kid-friendly AI experiences on real hardware. This is an on-site role in NYC with equity and benefits.