> Markdown version of [/jobs/ext/3872901-principal-data-scientist-user-ecosystem](https://www.wearedevelopers.com/jobs/ext/3872901-principal-data-scientist-user-ecosystem). Every page supports `.md` or `Accept: text/markdown`. Links point to the HTML versions so they work for humans too. Agent guide: [/agents.md](https://www.wearedevelopers.com/agents.md).

---

# Principal Data Scientist, User Ecosystem

- **Company:** reddit Inc.
- **Location:** United States (Remote available)
- **Experience:** Expert
- **Salary:** $313,000.0
- **Contract:** Temporary contract
- **Skills:** Software Code Optimization, Machine Learning, Pytorch, Deep Learning, Feature Extraction
- **Published:** October 22, 2026
- **Apply:** https://job-boards.greenhouse.io/reddit/jobs/8289345

## About the Role

* Deep expertise in at least one relevant area, with the breadth and curiosity to work across adjacent domains.
 * A deep understanding of how to model and optimize systems involving users, content, communities, and feedback loops.
 * Ability to frame and lead the most ambiguous questions, identify the most important uncertainties, and develop a rigorous path from evidence to action.
 * Exceptional technical judgment across model design, objective selection, validation, experimentation, and production tradeoffs.
 * Advanced knowledge of modern machine-learning methods for behavioral and content data, including representation learning and sequential or contextual models. Experience with deep-learning frameworks such as PyTorch or JAX.
 * Experience working across Product, Engineering, Research, and other partner teams.
 * Excellent written and verbal communication, with the ability to influence senior stakeholders and explain technical ideas clearly.
 * Significant experience applying data science, machine learning, statistics, experimentation, or causal inference to complex consumer products.

## Description

* Set the scientific direction for high-impact Consumer problems spanning discovery, relevance, personalization, user growth, retention, content, and communities.
 * Build a durable understanding of users, their intent, their needs, and the behaviors that lead to lasting value
 * Develop models and frameworks that represent users, content, communities, and their relationships over time for use in systems that operate at scale
 * Determine how to measure consumer and ecosystem health when objectives compete and short-term engagement may differ from long-term value.
 * Set learning agendas and steer experimentation strategy to distinguish durable improvement from temporary metric movement.
 * Build state-of-the-art measurement systems to evaluate heterogeneous effects across user personas, acquisition cohorts, platforms, content types, and community stages, and guide their actionability in production environments
 * Ensure coherence around ecosystem interactions including feedback loops, selection effects, interference, distribution shift, content supply, and other ecosystem risks.
 * Translate complex technical findings into clear product and business decisions.
 * Develop exceptional scientists through mentoring and influence data science org health and direction