Research Engineer, Post-Training (All Industry Levels) jobs in United States
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Character.AI · 2 weeks ago

Research Engineer, Post-Training (All Industry Levels)

positionUnited States
timeFull-time
remoteRemote
seniorityMid, Senior Level

Character.AI is a company that empowers people to connect, learn, and tell stories through interactive entertainment. As a Research Engineer on the Post-Training team, you will be involved in fine-tuning AI models, optimizing their performance, and ensuring quality, directly contributing to advancements in AI technology.

AppsArtificial Intelligence (AI)Foundational AIGenerative AIInformation TechnologyMobile AppsSoftware
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H1B Sponsor Likelynote

Responsibilities

Develop alignment algorithms and loss functions to improve data sample efficiency
Write data pipelines to process diverse web data into a format models can ingest
Identify quality signals to understand our model’s performance in the real world
Design sampling algorithms to improve serving efficiency of large generative models

Qualification

PhDEquivalentMachine learning techniquesData pipelinesGPUsAlignment algorithmsModel trainingA/B testingKubernetesDockerCloud deploymentResearch publications

Required

have at least PhD (or equivalent)
Write clear and clean production-facing and training code
Experience working with GPUs (training, serving, debugging)
Experience with data pipelines and data infrastructure
Strong understanding of modern machine learning techniques (reinforcement learning, transformers, etc)
Track-record of exceptional research or creative applied ML projects

Preferred

Experience with product experimentation and A/B testing
Experience training large models in a distributed setting
Familiarity with ML deployment and orchestration (Kubernetes, Docker, cloud)
Publications in relevant academic journals or conferences in the field of machine learning

Company

Character.AI

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Character.ai provides open-ended conversational applications in which users create characters and converse with them.
dateFounded in 2021
location
Menlo Park, California, USA
people-size51-200 employees
web-link
https://character.ai

H1B Sponsorship

Character.AI 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 (9)
2024 (16)
2023 (6)
2022 (1)

Funding

Current Stage
Growth Stage
Total Funding
$150.08M
Key Investors
Andreessen Horowitz
2023-03-23Series A· $150M
2023-01-24Seed· $0.08M

Leadership Team

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Karandeep Anand
CEO
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Company data provided by crunchbase