Twenty is seeking a mid-level AI Engineer for an in-office position in its Arlington, VA office to help build the next generation of cyber technologies that protect democracies worldwide. We're looking for someone with 4+ years of experience in developing and supporting ML and AI applications. In this role, you'll build, tune, and deploy language models that enhance our mission-critical cyber capabilities. You'll create and curate specialized datasets, fine-tune models for specific use cases, and implement efficient retrieval systems to augment AI reasoning. You'll join a world-class product and engineering team that delivers mission-critical solutions for U.S. national security, working in both cloud and on-premises environments to build AI systems that operate at machine speed. If you're passionate about applying cutting-edge AI techniques to solve complex technical challenges while making a direct impact on national security, we want to talk to you.
About the Company
At Twenty, we're taking on one of the most critical challenges of our time: ensuring democracies prevail in the digital age. We develop revolutionary technologies that operate at the intersection of cyber and electromagnetic domains, where the speed and complexity of operations exceeds human cognition. Our team doesn't just solve problems – we deliver game-changing outcomes that directly improve national security. We're pragmatic optimists who know that while our mission of defending America and its allies is challenging, we can succeed.
Role Details
Create, clean, and maintain high-quality training and evaluation datasets
Fine-tune language models ranging from small specialized models to medium foundation models
Develop and optimize model serving infrastructure for production environments
Develop retrieval-augmented generation (RAG) systems to enhance LLM capabilities with external knowledge
Implement prompt engineering strategies to optimize model outputs for specific applications
Integrate AI capabilities into applications using frameworks like LangChain and CrewAI
Design and implement evaluation frameworks to measure model performance
Collaborate with cross-functional teams to identify use cases where AI can add business value
Create technical documentation for AI systems and processes
Qualifications
Technical Skills & Experience
4+ years of professional software development experience with full-stack applications utilizing ML or AI
Strong skills in Python and deep learning frameworks (PyTorch, TensorFlow, or JAX)
Proficiency in LLM fine-tuning techniques (PEFT, LoRA, QLoRA)
Proficiency in vector and graph databases
Knowledge of dataset curation, cleaning, and preprocessing methodologies
Familiarity with model evaluation metrics and testing procedures
Experience with AI orchestration frameworks like LangChain or CrewAI
Education
Bachelor's degree in Computer Science, Software Engineering, or related fields, or equivalent practical experience
Security Requirements
Must be eligible to obtain and maintain a U.S. Government security clearance
Distinguishing Qualifications
Previous experience deploying models to production environments
Understanding of prompt engineering and model alignment techniques
Experience with distributed training systems
Knowledge of model quantization and optimization techniques
Additional Skills
Machine learning operations (MLOps)
Vector databases (Pinecone, Milvus, Weaviate)
Model serving technologies (vLLM, TensorRT, ONNX)
Containerization and orchestration (Docker, Kubernetes)
Experimentation tracking and version control for ML
Cloud platforms (AWS, GCP, or Azure)