Principal Applied AI Engineer

Bullhorn; United States; Remote; USD 175,000 - 200,000; Full time

Benefits offered by this job

Medical, Dental, Vision

401(k) Match

Paid time off

Annual bonus potential

Job summary

Bullhorn is seeking a Principal Applied AI Engineer to architect practical AI solutions that empower product teams to achieve their goals. You will guide the creation of a core platform of reusable tools, including an LLM client and evaluation harness, ensuring cost-effective, high-quality AI features.

The role combines strategic decision-making with hands-on development, focusing on when to use frontier LLMs versus bespoke models, while driving governance and MLOps best practices across the

Qualifications

• Proven leadership of cross-functional teams delivering AI-powered products.
• Hands-on expertise with modern LLM-based systems and traditional ML.
• Experience building reusable software components, libraries, and APIs.

Responsibilities

• Lead architectural design and implementation of AI systems for product teams.
• Develop a central hub for LLM interactions and a unified model API.
• Oversee evaluation frameworks, prompts, and governance for AI features.

Skills

Strategic leadership

Technical leadership

LLM-based systems

Platform design

A/B testing

Tools

LLM Client API

Evaluation Harness

Prompt Engineering

MLOps

Job description

Bullhorn's core purpose is to create an incredible customer experience, and the organization has a sharp focus on delivering very high quality products and services to its customers. The company culture is shaped by five Core Values: Ownership, Energy, Speed & Agility, Service, and Being Human. Each value, and its underlying definition, serves as a behavioral guide for employees as they interact with customers and fellow coworkers and is an embedded way of operating across our organization. Bullhorn is a fast-paced and dynamic environment where hard work and outstanding results are rewarded and celebrated. We value those that exhibit an eagerness to learn and a strong natural desire for continuous improvement and we encourage team members to stretch themselves, acknowledge challenges and learn from them. With a strong focus on growth, we provide ample opportunities for career development and prioritize promoting from within. We believe that leaders should care deeply about the development of their employees at all levels, emphasizing emotional intelligence and accountability. Our leaders collaborate closely to ensure the success of their teams, and we work together to achieve shared goals, creating a challenging and rewarding workplace for everyone.

About the Role

The Principal Applied AI Engineer will be a strategic and influential hands-on-keyboard individual contributor, responsible for architecting practical AI solutions that enable product leaders and teams to meet their goals. They will guide the teams to develop and maintain a core platform of reusable tools—including a central LLM client and evaluation harness—that dramatically speeds up development, and ensures the quality of, AI backed features. Critically, this role requires the strategic wisdom to determine the right tool for the job, making data-supported decisions for when a frontier LLM (commercial or open source) is the best approach versus when a bespoke machine learning model offers a faster, cheaper, and more effective solution. The Principal Engineer will act as the primary technical consultant for product and architecture leaders, ensuring every AI-powered feature is built on a foundation of excellence, while providing clear oversight of the cost, quality, and business value of all AI systems.

A Typical Day Will Include...

• Strategic & Technical Leadership: Serve as the primary point of contact and principal consultant for product and architecture leaders during the design and implementation of all AI systems.
• Champion a pragmatic, results-oriented approach to AI, ensuring the team focuses on practical (Applied) solutions that enable product teams to build high quality AI backed features.
• Establish the strategic framework for deciding when to use large language models versus bespoke ML models or traditional NLP, based on performance, cost, and speed.
• Lead the technical development of dedicated/bespoke ML models for specialized tasks where they are the superior option.
• Platform & Asset Development: Oversee the evolution of internal services into a robust, central hub for all LLM interactions.
• Drive the creation and maintenance of a standardized LLM client that provides a unified API for interacting with various models (e.g., OpenAI, Anthropic, open-source).
• Drive the creation, maintenance and expansion of a catalog of reusable code libraries, tools, and well-vetted prompts that provide product teams with an “80% solution” to accelerate their development cycles.
• Drive the standardization of an internal skills library for development.
• Diagnose issues preventing adoption and advise on fixes and improvements for the continuous improvement of the standard toolset
• Own and enhance the model evaluation harness to allow for rapid prototyping, A/B testing, and quality measurement of AI solutions.
• Own the AI gateway solution to support users, refine configuration, and monitor efficiency and cost
• Governance & Performance Oversight: Provide regular, clear insights to leadership on the value, ROI, and total cost of ownership of our AI initiatives.
• Establish and govern best practices for the entire ML lifecycle, including prompt engineering, data privacy, model safety, and MLOps.

This Role Is a Fit for You If...

• You are a Pragmatic Innovator: A leader who is passionate about cutting-edge AI but is fundamentally driven by solving real-world problems and delivering business value.
• You have Deep Technical Expertise: Extensive hands-on experience in both modern LLM-based systems (prompt engineering, RAG, fine-tuning, agentic workflows) and traditional machine learning (e.g., classification, regression, NLP).
• You are a Platform Builder: Proven experience designing, building, and maintaining reusable software components, libraries, and APIs that are used by other engineering teams.
• You are a Consultative Leader: Exceptional communication skills with the ability to explain complex technical trade-offs to both technical and non-technical stakeholders. Experience acting as an internal consultant or solutions architect is highly desirable.
• You are Data-Driven: Obsessed with measurement. Has a track record of implementing systems to track performance, quality, and cost, and using that data to make informed decisions.

The annual base salary range for this position is $175,000 - $200,000. In addition, this role is eligible for an annual target bonus & a comprehensive benefits package.

Compensation and Transparency Statement

The posted range represents the good-faith estimate of what we expect to pay for this role at the time of this posting. We may ultimately pay more or less than the posted range, and the range may be modified in the future. Actual pay within the range will be based on factors such as, but not limited to, experience, skills, qualifications, geographic location, internal equity, and business or organizational needs and affordability. In accordance with state and local pay transparency laws we disclose salary ranges in all job postings and provide additional information upon request.

What we offer...

Benefits eligibility effective DAY ONE including Medical, Dental, Vision, 401(k), 401(k) Match, and more Unlimited Planned Paid Time Off Global Mental Health Support On-Demand Learning & Development Quarterly paid volunteer days Lucrative Employee Referral Program (eligible for prior to your first day) Company-wide mentor program Bullhorn's core purpose is to create an incredible customer experience, and the organization has a sharp focus on delivering very high quality products and services to its customers. The company culture is shaped by five Core Values: Ownership, Energy, Speed & Agility, Service, and Being Human. Each value, and its underlying definition, serves as a behavioral guide for employees as they interact with customers and fellow coworkers and is an embedded way of operating across our organization. We are a people-first culture where everyone’s contribution is valued and respected. We're looking for smart, forward-thinking individuals who aren't afraid to challenge the status quo and bring fresh perspectives to the table. If you're someone who thrives in a casual, yet fast-paced and agile environment, we'd love to have you join us. For the past 25 years, Bullhorn has dedicated itself to building industry-leading, cloud-based software for the staffing and recruitment industry. Through partnerships with 10,000 customers globally, Bullhorn has built a vast knowledge base of recruitment best practices and deep domain expertise to help firms scale their businesses. Founder-led and headquartered in Boston, Bullhorn employs 1,400 people across 14 countries focused on delivering an incredible customer experience – its core mission. To learn more, visit www.bullhorn.com.