Staff Software Engineer - Applied ML



Software Engineering, Data Science
Menlo Park, CA, USA
Posted on Saturday, April 13, 2024

About us

Character’s mission is to empower everyone with AGI. Our vision is to enable people with our technology so that they can use Character.AI any moment of any day.

Character.AI is one of the world’s leading personal AI platforms. Founded in 2021 by AI pioneers Noam Shazeer and Daniel De Freitas, Character.AI is a full-stack AI company with a globally scaled direct-to-consumer platform. As of 2023 that platform was #2 in the space in user engagement. Character.AI is uniquely centered around people, letting users personalize their experience by interacting with AI “Characters.” The company achieved unicorn status in 2023 and was named Google Play’s AI App of the Year.

Noam co-invented the key tech powering LLMs and was recently named to TIME100’s Most Influential People in AI list. TIME called him “one of the most important and impactful people of the space’s past, present, and future.” Daniel created and led LaMDA, the breakthrough conversational tech project currently powering Bard.

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The platform team at Character bridges ML Engineering and Data Engineering to accomplish the following:

  1. Build best-in-class ML systems for our product using language models and traditional methods.

  2. Provide high quality data for analytics and model training.

  3. Remove the accidental complexity of Data Engineering tasks to empower ML Researchers, SWEs, and Data Scientists to move as quickly and confidently as possible.

  4. Make data go vroom while gpus go brrr!


  • Design, implement, and iterate on Applied ML systems like search, recommendations, and RAG in collaboration with our Research and Backend teams.

  • Own family of classifiers for async user-understanding

  • Interface with our Growth and Data Science teams to understand what levers we have to improve engagement and user experience.


  • Expertise building ML systems from scratch.

  • Experience leading teams of MLEs and Backend engineers on machine learning projects.

  • Solid understanding of Spark and ability to write, debug and optimize Spark code. Apache Spark on K8s a plus.

  • Experience building production systems in languages like Go, Python, SQL, Java, Scala

  • Experience designing and executing AB tests.

  • 2+ years experience with Kubernetes.

Applied ML, Recommendations, Retrieval, Embeddings, Tensorflow, Pytorch, XGBoost, Spark, Dataflow, Apache Beam, ML Platform, Search, Recommendations, Feature Stores

Character is an equal opportunity employer and does not discriminate on the basis of race, religion, national origin, gender, sexual orientation, age, veteran status, disability or any other legally protected status. We value diversity and encourage applicants from a range of backgrounds to apply.