• Location: Lisbon or Remote

• Department: AI team - Scoring and Metrics

About Us:

ELSA is a global leader in AI-powered English communication training, dedicated to transforming how people learn and speak English with confidence. Founded in 2016 and headquartered in San Francisco, we operate across the U.S., Vietnam, Portugal, Indonesia, Brazil and Japan.

Powered by proprietary speech-recognition technology and generative AI, ELSA delivers real-time, hyper-personalized feedback to help learners improve pronunciation, fluency, and overall communication effectiveness. With over 50 million learners and 1 billion hours of anonymized speech data, ELSAs depth of language training intelligence is unmatched in the industry.

Our B2B flagship platforms ELSA Enterprise and ELSA Schools empower organizations and educational institutions to elevate communication capabilities and unlock personal and professional opportunities for their people. We design engaging, bite-sized learning experiences that adapt to each learner's goals and context, ensuring measurable improvement and lasting confidence.

Our vision is to become the global standard for real-time English communication training, enabling 1.5 billion language learners worldwide to speak clearly, be understood, and share their stories with the world.

Backed by world-class investors including Googles Gradient Ventures, Monks Hill Ventures, and SOSV, ELSA has been recognized among the top global AI innovators:

• Forbes Top 4 Companies Using AI to Transform the World

• Research Sniper Top 5 Best AI Apps

• ASU+GSV EdTech 150

• CB Insights Top 100 AI Companies

Join us in shaping the future of language learning and empowering millions to unlock opportunity through confident communication.

Role Summary:

You will be joining the AI Research Team, a group of experts dedicated to advancing AI-driven language learning technologies.

We are seeking a skilled applied Machine Learning Engineer to design, develop, and deploy the core machine learning systems that power ELSA's personalized language learning experience. This role focuses on enhancing our automated scoring systems for spoken English, developing robust methods for tracking user proficiency across various skills, and contributing to the evolution of our adaptive learning algorithms. The ideal candidate has a strong foundation in machine learning, ideally with experience in speech processing or NLP, and possesses excellent programming skills. You will work closely with researchers, data scientists, and engineers to produce scalable, production-ready ML systems that directly impact millions of learners.

Key Responsibilities:

• Develop and deploy machine learning models for ELSA's automated analysis of spoken proficiency.

• Build and maintain machine learning systems to accurately track and model user proficiency across various English language skills.

• Contribute to the research, development, and refinement of ELSA's adaptive learning system to create more personalized and effective learning paths.

• Implement and manage robust evaluation frameworks to measure model performance, analyze user impact, and guide iterative improvements.

• Collaborate cross-functionally with researchers, engineers, data scientists, and product teams to integrate ML models and features seamlessly into ELSA’s platform.

What You Will Have
Must-Haves:

• Solid understanding and practical experience with machine learning fundamentals (e.g., classification, regression, sequence modeling, evaluation metrics).

• Strong background in machine learning, preferably with experience or academic focus in speech processing or Natural Language Processing (NLP).

• Proficiency in Python and common ML/data science libraries (e.g., scikit-learn, Pandas, NumPy, PyTorch/TensorFlow).

• Strong software engineering skills, including experience with APIs, databases, testing, and software development best practices.

• Experience working with data, including preprocessing, feature engineering, and analysis.

• Master's or PhD degree in Computer Science, Machine Learning, Data Science, Electrical Engineering, or a related quantitative field, or equivalent practical experience.

Nice-to-Haves:

• Hands-on experience with Automatic Speech Recognition (ASR), Text-to-Speech (TTS) systems, or other speech processing techniques.

• Experience developing NLP applications (e.g., text classification, sequence tagging, language modeling).

• Experience using Large Language Models (LLMs) for classification, feature extraction, or related tasks.

• Experience with cloud stacks (e.g. AWS - including Dynamo, S3).
  What We Offer

• Flexible work setup: Remote and hybrid work arrangements available.

• Comprehensive employee well-being benefits.

• Free ELSA Premium courses to polish your language skills

• Collaborative, international team culture.

• Opportunity to contribute to a fast-growing, well-funded Silicon Valley startup with global impact.