Language Lead - Japanese (Contract)
Role Summary
Join Cartesia as a Language Lead (Japanese) in a remote contract role focusing on quality and performance for voice AI.
About the Organisation
Our mission is to architect AI that learns from and interacts with the world like humans do.
We're pioneering the model architectures that will make this possible. Our founding team met as PhDs at the Stanford AI Lab, where we invented State Space Models or SSMs, a new primitive for training efficient, large-scale foundation models. Our team combines deep expertise in model innovation and systems engineering paired with a design-minded product engineering team to build and ship cutting edge models and experiences.
We're funded by leading investors at Index Ventures and Lightspeed Venture Partners, along with Factory, Conviction, A Star, General Catalyst, SV Angel, Databricks and others. We're fortunate to have the support of many amazing advisors, and 90+ angels across many industries, including the world's foremost experts in AI.
You will coordinate with the Human Evals Manager on project deliverables and timelines. Some examples of what your day-to-day work may include:
- Answer questions from annotators about guidelines, edge cases, or language-specific issues via an agreed project communication channel.
- Cascade new feedback, instructions, or rubric updates to annotators working on your projects.
- Listen to annotator-rated audio files and check whether their ratings and written feedback align with the rubric.
- Prepare written quality assessments for annotators with specific examples and recommendations.
- Listen to TTS output and provide ground truth assessments of pronunciation, prosody, and naturalness in your language.
- Update or expand sections of the annotation guidelines when you find gaps or edge cases.
- Prep and run calibration meetings with annotators.
- Hold office hours on a mutually agreed schedule during active studies so annotators can ask questions in real time.
- Develop onboarding materials and resources for new annotators.
- Write QA reports on annotation quality and calibration outcomes.
- Review production audio in your language and flag quality issues to the team.
- Investigate language-specific issues reported by customers and identify root causes.
- Audit datasets for linguistic accuracy, completeness, and consistency.
Minimum Requirements
This is a 1099 contract opportunity and will not be eligible for the benefits below. Language Leads work on an ongoing basis, renewable by mutual agreement. You will control your own methods for completing assigned work, supply your own equipment, and are responsible for your own taxes. You must be authorized to work in your country of residence.
Note: Cartesia participates in E-Verify and will provide the federal government with Form I-9 information to confirm employment eligibility after hire.
- Native-level proficiency in Japanese as spoken in Japan.
- Experience with data annotation, transcription, or language quality assurance.
- Strong foundation in linguistics or a related field, with the ability to apply concepts like phonetics, prosody, and intonation when evaluating speech and writing annotation guidelines.
- Strong written English proficiency. All guidelines, feedback, reports, and team communication are in English.
- Ability to write clear, structured instructions and deliver specific, actionable feedback to annotators.
- Comfortable working with data and metrics such as inter-rater agreement scores, audit spreadsheets, and structured feedback templates.
- Self-directed and able to manage feedback cycles, QA reviews, and data projects without close oversight.
- Experience writing or maintaining annotation guidelines or rubrics.
- Experience training, mentoring, or managing other annotators.
- Experience with audio evaluation, TTS, or STT.
- Conversational spoken English proficiency for meetings and calibration syncs.
- Experience working with distributed, remote teams.
Working Conditions
💰 Compensation Competitive base salary alongside attractive equity package.
🩺 Health Insurance Fully covered medical insurance along with dental and vision for you and your family.
🧑🧑🧒🧒 Parental Leave 9 weeks paternity & 12 weeks maternity leave
🏦 401(k)
🚆 Commuter Allowance A monthly stipend to help you get to and from the office.
🏖️ Flexible PTO Take as much time as you need to recharge your batteries.
🍲 Meals & Snacks Lunch, dinner and plenty of snacks, provided daily.
🦖 Your own personal Yoshi
Eligibility Criteria
This is a remote position suitable for native Japanese speakers with a background in linguistics.
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