Backend Software Engineer
Location: San Francisco (Hybrid - in-office 3+ days/week in downtown SF)
About Billables AI
At Billables AI, we’re building an AI-powered SaaS platform to transform how professional service providers work, freeing them to focus on the most creative and high-value parts of their business. We build workflows that eliminate manual overhead - starting with automated billable time tracking for attorneys.
We sit close to the core of how our customers operate and generate revenue. The systems we build need to be reliable, scalable, and thoughtfully designed, and the features we deliver have real, day-to-day impact for our fast-growing customer base.
We’re a small, experienced team based in San Francisco. We move quickly, prioritize impact, and empower engineers to drive projects end-to-end.
About the role
We’re looking for a backend engineer to help build and scale the core systems behind our platform. You’ll work on problems from early ideas through production - shaping requirements, making technical decisions, and working cross-functionally to deliver the right outcomes. You’ll work closely with backend, frontend, and AI engineers, and collaborate with leadership, go-to-market, and customers directly.
You might be a senior engineer who’s worked in startups before, or someone earlier in your career who’s already shown you can get a lot done and take initiative in fast-moving environments. This role is a great fit if you like owning meaningful parts of a system and making pragmatic trade-offs to ship.
What you’ll work on
Design, build, and maintain backend services (Python, gRPC, Postgres, Redis)
Work across a service-oriented architecture and integrate with third-party systems
Own projects end-to-end: clarify requirements, propose solutions, implement, and iterate in production
Scale systems that ingest and process large volumes of activity data
Improve reliability, performance, and observability across services
Make thoughtful trade-offs between speed, quality, and scalability
Contribute to system architecture and long-term technical direction
Step outside your primary lane when needed - frontend, infrastructure, etc
What we’re looking for
Strong track record of deploying and maintaining high-quality, production-ready code in a modern environment
Proficiency in Python and strong backend fundamentals (APIs, data modeling, system design)
Experience building and scaling distributed systems or microservice architectures
A high ownership mindset - you take responsibility for outcomes, not just code
Comfort moving quickly and making decisions without perfect information
Actively use AI tools (LLMs, copilots, etc.) as part of your day-to-day development workflow
Clear communicator who can engage with both technical and non-technical stakeholders
Experience in early-stage or fast-moving environments
Nice to have
Experience with gRPC or similar RPC frameworks
Experience with DevOps/infrastructure (Docker, IaC, CI/CD)
Experience working with AI/ML systems or integrating LLMs into products
Tech stack (not exhaustive)
Python, gRPC, Postgres, Redis, Azure, Docker
Why this role
You’ll work on systems that are central to how our customers run their business
You’ll have real ownership early - not just implementation work
You’ll be part of a small, collaborative team where your decisions meaningfully shape the product and architecture
How to apply
Ready to join our team at Billables.ai? Please send your resume to hiring@billables.ai. We look forward to hearing from you!