Research Engineer, Applied Research

At Sierra, a company specializing in customer-facing AI agents, the engineering team focuses on advancing voice AI and machine learning models to improve customer interactions. The role involves tackling complex applied AI problems, developing and deploying models, and working with large datasets to enhance Sierra’s AI agents. The team values craftsmanship, customer obsession, and a high level of technical expertise, working primarily in an on-site environment in San Francisco.

The research engineer will analyze ambiguous problems, translate them into machine learning tasks, and develop solutions that balance quality, speed, and cost. Daily activities include fine-tuning models, evaluating their performance, and collaborating across teams to move ideas from experimentation to production. The role demands strong judgment, deep data experience, and the ability to operate across the ML stack to deliver impactful results.

Candidates should have substantial experience in deploying ML systems, especially in speech, language, or multimodal models, with a background in applied ML fields like search, ranking, or recommendations. The position requires a degree in a related field or equivalent experience, with a preference for those familiar with reinforcement learning, large-scale datasets, and real-world evaluation metrics. The work is full-time, on-site, in San Francisco, emphasizing innovation and customer-focused AI development.