Senior Machine Learning Engineer

Position Name: Senior Machine Learning Engineer

Location: Boulder, CO

Employment Type: Full-time

Notes: Direct Hire. No third-party assistance is approved for this role.

About The Job: 

At Jaxon, we’re focused on making AI trustworthy for mission-critical environments. Our core technology is built to enable the safe deployment of AI in high-stakes settings, particularly across the Department of Defense. While our company supports both commercial and government applications, this role is dedicated to the defense side. As a Machine Learning Engineer at Jaxon, you’ll be embedded on a sensitive project designed to help solidify the U.S. Space Force’s ability to use AI reliably. The work centers on advancing machine learning capabilities to meet the rigor and reliability required for national security operations. Existing SECRET security clearance strongly preferred; eligibility to obtain clearance is required if not already held.

Jaxon’s product, Domain-Specific AI Language (DSAIL), forms the basis of most of our deployments. This role will focus on increasing security and reliability for our customers through implementing and building on DSAIL’s capabilities. A particular emphasis is placed on addressing the fundamental limitations of LLMs – specifically around context and logical reasoning. 
 

The basics of this role requires the ability to:

• Collaborate Across Teams: Work with cross-functional, geographically distributed teams to integrate ML models into our existing systems and workflows, enhancing product capabilities.
• Optimize Data Processing and Model Performance: Conduct comprehensive data management including preprocessing, feature engineering, and model evaluation to improve accuracy and efficiency.
• Technical Proficiency with an NLP focus: Demonstrate solid machine learning engineering experience, particularly with NLP applications and unstructured data in a cloud environment. Fluency in Python is essential.
• Understand Large Language Models: Operationalize intimate familiarity with the model deployment process, optimization of LLM parameters for specific behaviors, and a general understanding of LLM functionality and use cases.  Previous experience with AI/LLM governance and guardrail development is a big plus.

Soft Skills:

• Ability to context switch as needed
• Ability to communicate findings and recommendations clearly and constructively to peers, management, partners, and customers
• Ability to effectively explain highly technical details to less technically focused decision makers
• Ability to compartmentalize different projects with different goals

Requirements:

• Python
• Python Data Science Stack - NumPy, Pandas, Scikit Learn, various deep learning and NLP libraries including demonstrable experience with libraries relevant to data manipulation.
• Langraph, LlamaIndex and/or other agentic libraries
• Docker, Docker Compose, K8s and related container orchestration technologies
• Hands-on experience running local LLMs using technologies such as Ollama and Transformers
• Have a comfort level building and training and/or fine-tuning models, not just calling cloud APIs, but you’re resourceful enough to recognize when you can use cloud APIs whenever you can get away with it.
• Aren’t afraid of digesting academic papers, but you understand that it’s code that matters.
• Have an understanding of both the fundamentals and applications of different NLP approaches. 

Nice-To-Haves:

• Some familiarity with knowledge representation
• Familiarity with so-called “hybrid databases” like Apache AGE
• Familiarity with Model Context Protocol (MCP)
• Previous experience with consulting on Defense projects involving software development, data science support, especially at service labs or joint commands.

About Jaxon: Jaxon’s is on a mission to make AI trustworthy. Developed through R&D with the U.S. Department of Defense, Jaxon converts complex rule sets—whether from policy manuals, onboarding playbooks, compliance protocols, or SME conversations—into executable logic. It extracts the key ‘questions’ hidden in unstructured docs, builds rule-driven evaluators, and tracks what’s being asked and why. The result: consistent, auditable, and provable reasoning—bringing structure, oversight, and trust to LLM-driven workflows.

What Makes Jaxon Different?
 

• Human First: Our leaders get it — life happens. Whether it’s flexible working hours or understanding the need for a mental health day, we prioritize your well-being. Our CEO recognizes that happy people do the best work and he backs that up with an empathetically led culture – and I’m not just saying that because he’s going to read this post. 
• Laid-Back Culture: We know that the best work comes from a place of comfort and authenticity. At Jaxon, you’re encouraged to be yourself, dress casually, and embrace your quirky side. It’s just one of the benefits of being an early-stage, high-growth startup.
• Tech Lover's Dream: From hackathons to tech talks with industry leaders, we fuel our passion for innovation with constant learning and development opportunities.
• Grunt Work to Grand Projects: Every task you tackle, big or small, matters. You think I’m writing job descriptions for fun? Sometimes things need to get done and it’s an all hands on deck situation to get them to the finish line. We're looking for team players who understand that achieving groundbreaking AI innovations sometimes involves rolling up your sleeves to tackle the essential, yet less glamorous tasks.

Added Perks:

• Unlimited PTO: (seriously!)
• Comprehensive benefits: Health, dental, and vision insurance + 401k matching
• Competitive Salary: We provide competitive compensation packages commensurate with experience
• Stock Options: All compensation plans include stock options - join now and benefit from future acquisitions
• Holidays Off: ALL federal holidays are paid time off. 
• Relocation Expenses: We are happy to assist with relocation expenses to help make your transition as smooth as possible.

About You: You're the type of person who's naturally driven—not necessarily because you built a rocket in your backyard as a kid, but because you have a genuine curiosity about the world of technology. In your spare time, you might find yourself deep-diving into technology subreddits, following the latest industry trends, or exploring which companies are innovating and how. Your passion isn't just about staying informed; it's about thinking how you can take these emerging concepts and scale them up, make them faster, or more impactful. At Jaxon, we're looking for someone who sees a baseline and instinctively wants to build beyond it. If you’re ready to take what exists and make it extraordinary, you’ll fit right in.

We are looking for somebody who thrives in an environment where day-to-day priorities and tasks may rapidly change. The role is not a fit if you value "business as usual".

We value team members who are bold enough to pitch creative ideas, even if they're still rough around the edges or might not make the final cut.

Education and Length of Experience

Applicants should have a bachelor's degree in Computer Science or similar. An MS or PhD in Computer Science, Statistics, Physics, Mathematics or any related Engineering field preferred. Candidates should have a minimum 5 years of experience in similar roles. 

Jaxon is proud to be an equal opportunity workplace and is an affirmative action employer. We are committed to equal employment opportunities regardless of race, color, ancestry, religion, sex, sexual orientation, age, marital status, disability, or Veteran status.