Staff AI/ML Engineer (LLMs)

Company: CACI
Location: Aurora
Posted on: April 6, 2026

Job Description:

Job Title: Staff AI/ML Engineer (LLMs) Job Category: Science Time Type: Full time Minimum Clearance Required to Start: TS/SCI Employee Type: Regular Percentage of Travel Required: Up to 10% Type of Travel: Local Anticipated Posting End: 8/31/2026 The Opportunity: The Staff AI/ML Engineer (LLMs) will lead the development of Agentic AI capabilities and other LLM based capabilities for a multitude of mission management applications. Responsibilities: Lead and mentor a multidisciplined team consisting of developers and researchers to implement machine learning algorithms to solve a broad set of challenges for our various customers Lead and mentor a multidisciplinary team delivering advanced AI/ML solutions Apply LLMs to complex domain-specific problems and operational workflows Adapt and fine-tune foundation models for specialized use cases Design and implement retrieval-augmented generation (RAG) systems and semantic search architectures Build production-grade LLM applications and agentic systems Deploy scalable AI solutions across cloud, on-prem, and hybrid environments Analyze large, multi-modal datasets to extract meaningful features and actionable insights Translate emerging research into applied, mission-relevant capabilities Communicate technical strategy, status, and risks to internal and external leadership Qualifications: Required: B.S. in machine learning, computer science, mathematics, or related fields 8 years of experience, preferably in software development or as a data scientist with 2 years of building LLM applications using some of the following: Fine-tuning foundational models Steering Techniques (e.g Sparse auto encoders, representation tuning) Building adapters to use foundational models (e.g. PEFT, llama factory) Prompt engineering techniques / Inference time techniques (e.g. chain of thought, tree of thoughts, etc.) Using Retrieval Augmented Generation techniques to populate and query vector databases (e.g. Weaviate, pinecone, pgvector) Using LLM Frameworks (e.g. LangChain, DSPy, Microsoft Agent Framework) Using AI APIs ( e.g AWS Bedrock, OpenAI) Using LLM deployment frameworks (eg llama.cpp, vllm, tgi) Developing UIs with ReAct Experience leading an interdisciplinary team of researchers and software developers and working with a program manager to define project scope and schedule to ensure we meet project milestones as defined by our customers Experience with Python and data science / machine learning libraries (e.g. NumPy, Pandas, Polars, scikit-learn, etc.) Experience contributing on a team using version control (e.g. git, GitLab, Bitbucket) Active TS/SCI U.S. Government Security Clearance Desired: M.S. or PhD in machine learning, computer science, mathematics, or related fields Experience leading an interdisciplinary team of researchers and software developers Experience with any of the following: Large Language Models and experience identifying ways to incorporate them into new domains and applications Applying Transformer-based architectures to domains in other areas outside of Natural Language Processing (NLP) such as computer vision Natural Language Processing algorithms such as BERT Reinforcement learning and familiarity with Gymnasium Gym, OpenEnv, TorchRL, RLlib, and Stable Baselines Applying clustering algorithms and/or deep neural networks to real life problems Implementing tracking and pattern-of-life algorithms Experience with GenAI Ops techniques (e.g. LLM-as-a-judge) and frameworks (e.g. LangFuse, MLFlow, Arize Phoenix) Experience with Machine Learning libraries and frameworks such as HuggingFace and LangChain Experience with Linux Experience with CUDA and Python libraries such as CuPy, Numba, CuSignal, CuDF, etc. Familiarity with using AWS cloud computing resources such as EC2, S3, Lambda, etc. Experience with any of the following additional languages: Java, C++, Rust, Go, and/or C# Experience in application deployment, virtualization, and containerization (e.g. Podman, Docker, Kubernetes, Rancher) Experience shaping and writing proposals Adjudicated Counter Intelligence or Full Scope Polygraph - What You Can Expect: A culture of integrity. At CACI, we place character and innovation at the center of everything we do. As a valued team member, you’ll be part of a high-performing group dedicated to our customer’s missions and driven by a higher purpose – to ensure the safety of our nation. An environment of trust. CACI values the unique contributions that every employee brings to our company and our customers - every day. You’ll have the autonomy to take the time you need through a unique flexible time off benefit and have access to robust learning resources to make your ambitions a reality. A focus on continuous growth. Together, we will advance our nation's most critical missions, build on our lengthy track record of business success, and find opportunities to break new ground — in your career and in our legacy. Pay Range : There are a host of factors that can influence final salary including, but not limited to, geographic location, Federal Government contract labor categories and contract wage rates, relevant prior work experience, specific skills and competencies, education, and certifications. Our employees value the flexibility at CACI that allows them to balance quality work and their personal lives. We offer competitive compensation, benefits and learning and development opportunities. Our broad and competitive mix of benefits options is designed to support and protect employees and their families. At CACI, you will receive comprehensive benefits such as; healthcare, wellness, financial, retirement, family support, continuing education, and time off benefits. Since this position can be worked in more than one location, the range shown is the national average for the position. The proposed salary range for this position is: $98,500-$206,800 CACI is an Equal Opportunity Employer. All qualified applicants will receive consideration for employment without regard to race, color, religion, sex, pregnancy, sexual orientation, age, national origin, disability, status as a protected veteran, or any other protected characteristic.

Keywords: CACI, Vail , Staff AI/ML Engineer (LLMs), IT / Software / Systems , Aurora, Colorado