AI Engineer

Location: San Francisco (Hybrid - in-office 3+ days/week in downtown SF)

About Billables AI

Billables AI is building the AI-powered operating layer for professional service firms, and we're starting where the pain is deepest: the legal industry. Our platform automates the manual overhead that slows lawyers down, bringing together intelligent timekeeping, work activity capture, and operational visibility so firms can understand how work happens and build a more efficient, profitable practice. The best work happens when people aren't buried in administrative burden, and that's exactly the problem we're solving.

Named Legal Tech Company of the Year by Law.com in 2026, Billables AI is one of the fastest-growing companies at the intersection of AI and legal technology. Our team brings together expert AI researchers and veteran startup builders who know how to move fast, build with conviction, and deliver software that sits at the core of how our customers work and generate revenue. Based in San Francisco, we empower everyone on the team to drive meaningful work end-to-end.

About the role

We’re looking for an AI Engineer to build and evolve customer-facing AI features across our platform. This is an applied AI engineering role focused on integrating modern LLM capabilities into real production workflows. You’ll work closely with backend and frontend engineers, leadership, and customers to design, implement, evaluate, and improve AI-powered experiences used daily by professional service teams.

We’re looking for engineers with strong technical fundamentals, practical experimentation skills, and experience building AI-powered systems in production environments - especially customer-facing LLM applications. You may be a senior engineer with deep experience building AI systems, or someone earlier in your career who’s demonstrated strong ownership and a high rate of growth.

What you’ll do

Apply LLMs and modern AI approaches to solve user pain points around personalization and automation of complex tasks
Build prompt pipelines, retrieval systems, and agentic workflows for customer-facing products
Improve classification, extraction, summarization, and automation systems across large volumes of activity data
Design practical evaluations and experiments to improve AI quality and guide product decisions
Build and extend backend services and APIs in Python
Own projects end-to-end: clarify requirements, implement solutions, and iterate in production
Collaborate closely with engineers, leadership, and customers to improve product experiences
Help shape how we use AI tooling and AI-assisted engineering workflows internally

What we’re looking for

Experience building and integrating AI-powered systems in production environments, particularly customer-facing LLM applications
Strong software engineering fundamentals and hands-on experience working within Python backend architectures
Experience designing experiments and evaluation frameworks to measure and improve AI quality and user outcomes
Comfort moving quickly and making decisions without perfect information
High ownership mindset and ability to independently drive projects end-to-end
Clear communicator who collaborates effectively across technical and non-technical stakeholders
Active use of AI development tools (LLMs, copilots, etc.) in day-to-day workflows
Experience in early-stage or fast-moving environments

Nice to have

Experience with distributed systems, gRPC, or service-oriented architectures
Experience deploying and operating AI systems in cloud environments
Experience with AI infrastructure, MLOps, or large-scale evaluation systems

Why this role

You’ll work on systems that are central to how our customers run their business
You’ll have meaningful ownership and influence early
The opportunity to work within a highly collaborative, deeply technical team to develop leading-edge AI solutions