Data Science / ML Intern (Fall 2025)

About BoldVoice

BoldVoice is a communication coaching app that helps ESL professionals find their clearest and most confident voice so they can succeed in the global workplace. Combining bite-sized videos from Hollywood accent coaches with real-time AI feedback on pronunciation, BoldVoice delivers an engaging and personalized learning experience at a fraction of the price of traditional coaching.

About the role

BoldVoice (YC S21) is an accent training app that empowers non-native English speakers to speak clearly and confidently. Users watch video lessons on pronunciation from Hollywood accent coaches, and improve their fluency by practicing and getting instant feedback from the app's speech artificial intelligence. So far, the app has been downloaded by over 3 million users and has been featured on Forbes, TechCrunch, and LinkedIn Learning. We are a small, nimble team, with a big mission to help 1 billion people improve their English skills and advance their careers.

Role and Responsibilities

We are looking for a Data Science / Machine Learning intern to support our core speech AI and ML product initiatives. If you’re analytical, detail-oriented, and excited about working with real-world AI systems in production, this role is for you.

Responsibilities include:

Rigorously test our proprietary pronunciation scoring models to identify edge cases, biases, and performance anomalies

Support data cleaning, labeling, and preprocessing workflows for model training and evaluation

Collaborate closely with ML engineers to triage and debug model-related issues

Improve internal tools, dashboards, and documentation used for data analysis and model QA

Qualifications:

Current student or recent graduate (BA/BS/MS) in Computer Science, Data Science, Statistics, Linguistics, or a related field

Prior experience or coursework in data analysis, ML, or NLP strongly preferred

Familiarity with Python and basic data science tools (e.g., pandas, Jupyter, NumPy); bonus for SQL or PyTorch/TensorFlow

Bonus: knowledge of phonetics, speech technology, or the International Phonetic Alphabet (IPA)

Strong attention to detail, curiosity, and the ability to break down complex problems

Self-starter mindset: organized, scrappy, and able to work independently with minimal oversight

Must be US-based, NYC-local, and able to work in person (remote candidates will not be considered)

Must be able to dedicate at least 20 hours/week (ideally more)

Compensation & Perks

Paid internship: You will be paid an hourly rate

AI experience: You will be part of a ML engineering team training cutting-edge voice models

In-person immersion: You will work from our office in the Manhattan (Noho), and see firsthand how a fast-growing startup operates.

How to Apply

Share your resume

Share your availability (start date, end date, and number of hours per week)

Download the app, go through the onboarding, assessment, and first practice session, and provide suggestions for how the experience or pronunciation model output could be improved—from a product, UX, or ML perspective.

Technology

Our tech stack is: React Native, for iOS and Android mobile apps React, for web CMS Node/Express/PostgreSQL, for backend Heroku, for hosting Bugsnag, Mixpanel, NewRelic, Mailgun, as other services we use