Principal Engineer

About your role

As a Principal Engineer, you will drive the team’s technical direction and play a pivotal role in designing and architecting accounting software systems. This role involves mentoring team members, solving complex technical challenges, and delivering hands-on contributions as a full-stack leader.

You will work closely with engineers and cross-functional partners across Product, Design, and Quality Assurance to expand system capabilities. Your leadership will be instrumental in achieving the team’s objectives and advancing our technical vision.

What you'll do

Own Technical Direction and Architecture

• Set the technical direction for AI systems, including shared AI SDKs, guardrails, evaluation frameworks, feedback systems, and agentic workflow infrastructure
• Own architecture and technical strategy for complex backend and AI platform systems, from design through production
• Lead technical design for ambiguous, cross-functional initiatives, evaluating tradeoffs, aligning stakeholders, and driving implementation
• Evaluate and select technologies with a bias toward what ships well and scales sustainably

Build and Operate AI Systems

• Write production code as a hands-on individual contributor; this is not a role that delegates implementation to others
• Design and operate LLM-powered systems, including RAG pipelines, agentic workflows, evaluation infrastructure, guardrails, and model observability
• Own end to end reliability of AI systems, from design through structured output delivery
• Define quality benchmarks

Champion AI Native Development

• Champion and embed AI native development practices and tools, such as Cursor and Augment, to drive meaningful productivity gains across the team
• Foster a culture of rapid iteration, high velocity, and quality, including guiding the effective use of AI code generation
• Bring strong, informed opinions on how to get the most from AI-assisted development while maintaining reliability and correctness

Lead and Grow the Team

• Mentor engineers, raise the quality of technical decision making, and help the team execute with consistency
• Establish coding standards, review practices, and architectural documentation that scale as the team grows
• Help define what “good” looks like for a team building at speed without sacrificing quality
• Partner with recruiting to build and grow the team

Collaborate Cross Functionally

• Work closely with Engineering Managers, Product, Design, and QA to translate requirements into executable technical plans
• Participate actively in design reviews and roadmap discussions with a grounded, implementation-level perspective
• Handle most cross-team conflicts and technical decisions autonomously

AI Fluency

• Ability to critically evaluate AI-generated code and outputs, including identifying failure modes, regressions, and edge cases introduced by AI-assisted development
• Experience building and shipping production-grade software using AI-assisted workflows across the full SDLC
• Hands-on experience developing or integrating LLM-powered systems, such as agents, copilots, tool-using workflows, or multi-step reasoning systems
• Familiarity with patterns such as tool calling agents, planning and execution loops, and retrieval augmented generation (RAG)
• Demonstrated ability to leverage modern AI tools to improve development velocity, code quality, and problem-solving
• Experience contributing to AI-powered features, such as intelligent search, conversational interfaces, recommendations, and automation
• Working knowledge of LLMs, embeddings, semantic search, and RAG pipelines
• Ability to identify and evaluate opportunities to integrate AI capabilities into products and workflows

Qualifications

• Bachelor’s degree in Computer Science or equivalent work experience
• 13 to 17 years of experience in software development across building, integration, security, and architecture
• Previous experience building enterprise-grade APIs is a plus
• Previous experience leading a team is a plus
• Expertise in object-oriented programming with Python as the primary language
• Experience with front-end technologies such as React, CSS frameworks, HTML, and JavaScript
• Experience with relational databases such as Postgres and MySQL
• Experience with SQL database schema design and query optimization.
• Experience with cloud technologies, preferably AWS, and container technologies such as Docker and Kubernetes
• Experience with GraphQL and Apollo Server is a plus, but not required
• You must be flexible and adaptable, and comfortable operating in a fast-paced startup environment

At Juniper Square, we believe building a diverse workforce and an inclusive culture makes us a better company. If this role sounds like a fit, we encourage you to apply even if you do not meet all of the qualifications.