Senior Software Engineer (Artificial Intelligence)

Join Justworks, a company dedicated to helping businesses thrive by solving HR issues. As a Senior Software Engineer, you will be part of a small, autonomous team focused on building AI agents that transform operations at scale. You will take ownership of core components of the agent platform, architect the knowledge and memory infrastructure, and design the trust and safety framework. This is an opportunity to make a meaningful impact in a supportive and entrepreneurial environment.

• Design, build, and own core components of the agent platform, from the orchestration layer to the tool integrations connecting it to internal systems.
• Architect the knowledge and memory infrastructure, allowing agents to retrieve the data and act across our systems.
• Mentor other engineers on the team as it grows, contributing to their professional development and the overall success of the team.
• You are self-driven and like to work with others to remove roadblocks. You are curious and love to explore and learn new technologies. You have demonstrated the ability to build, deploy, and maintain large-scale, complex applications. You care more about solutions and impacting the customer experience than using a particular tool or framework
• You are product-minded. You look beyond the immediate task, seeking to understand the "why" behind the build and questioning whether it's the right product solution. You are comfortable contributing product thinking alongside engineering work
• You possess strong backend engineering fundamentals. You can confidently design, build, and operate production systems
• You are comfortable in a fast-paced, early-stage environment. You demonstrate a "scrappy" and resourceful approach, proactively identifying solutions and unblocking yourself without needing a fully defined path
• You demonstrate a strong ownership mindset. You are proactive, identify gaps, and drive initiatives to completion without waiting for explicit instructions. When encountering issues or ambiguity, you address them directly
• You are pragmatic and balance quality with speed. You understand when to optimize for long-term durability and when to iterate quickly. You prioritize pragmatism over being overly precious about code, but never compromise on quality in a way that creates future issues
• You are curious and eager to develop expertise in AI and LLMs. While deep research is not required, you are motivated to build practical, real-world products using these tools, specifically focusing on agent systems
• Hands-on experience with LLMs and AI agents (orchestration, RAG, tool/function calling, or similar)
• 5+ years of backend engineering experience building and operating production systems
• Product-minded: questions requirements and contributes to product decisions, not just execution
• Strong API design and system integration skills
• Proven ownership of complex projects in ambiguous, early-stage environments