Sr. Machine Learning Engineer I

We are hiring for a Sr AI Engineer to help design and improve voice-based AI agents for Taco Bell drive-thru operations. This role is perfect for early-career AI engineers or data scientists looking to expand their skills in LLM-based interaction design, speech system optimization, and production-quality prompt development. 

You’ll collaborate closely with advanced senior AI Engineers, MLEs, and QA to iterate on agent prompts, tune foundational models, and contribute to the overall agent experience for customers and employees. 

Prompt Engineering & Agent Design 

• Author and refine prompt instructions, chaining logic, and fallback strategies 
• Design and test multi-turn conversation flows aligned to Taco Bell brand voice 
• Build and maintain system personas and error handling routines 

Model Tuning & Evaluation 

• Fine-tune LLMs, ASR models, and embedding systems under supervision 
• Assist in running experiments using LoRA, distillation, or pruning methods 
• Contribute to agent evaluation metrics, regression tracking, and A/B tests 

Cross-Functional Collaboration

• Work closely with MLEs on model integration and performance tuning 
• Partner with QA and PMs to improve agent usability, reliability, and task success rates 
• Help manage RAG components, context retrieval chains, and structured data inputs 

Required Qualifications

• 5+ years experience in AI Engineering, Data Science, or ML-related roles 
• Proficiency in Python and AI frameworks (e.g., LangChain, HuggingFace, OpenAI APIs) 
• Understanding of prompt engineering, agent flows, and model evaluation principles 
• Interest in LLM tuning, ASR modeling, or speech interaction design 

Preferred Qualifications

• Experience with RAG, vector search, embeddings, or retrieval-based models 
• Exposure to ASR systems or speech pipelines 
• Familiarity with LoRA, distillation, or low-latency AI architectures 

This position is available exclusively to candidates located in Vietnam. Relocation support is not provided, and applicants must be currently residing in Vietnam to be considered.