Backend Engineer

Little Engine is building the AI-native back office for solo service providers such as personal trainers, stylists, tutors, massage therapists, and dog walkers. Their mobile app automates scheduling, payments, and client communication entirely over SMS, replacing multiple tools with an intelligent assistant. The company has closed a multi-million dollar pre-seed round and includes repeat founders with experience building award-winning apps.

• Senior-level experience shipping and operating production Python backend services (typically 5+ years)
• Strong Python fundamentals including async/await and typing
• Experience with REST API design
• Ownership of third-party integrations end-to-end, especially payments (Stripe) and calendars (Google Calendar/OAuth)
• Hands-on experience with FastAPI, SQLAlchemy (async), and Pydantic
• Comfortable working within Clean / Hexagonal architecture
• Experience with background processing using Celery and Redis
• Strong PostgreSQL skills including schema design and migrations (Alembic)
• Experience with platform SDKs such as Twilio, Firebase, Cloudflare R2/S3
• Comfortable with Docker, GitHub Actions CI/CD, and cloud deployment (GCP / Cloud Run or equivalent)
• Strong testing discipline including unit, integration, and end-to-end tests
• Ability to work across time zones with a US-based product team

• Build, ship, and maintain backend platform features from technical design through deployment and production monitoring
• Own a slice of the product end-to-end, including scoping work with product and designing implementations
• Collaborate with mobile and web engineers on API endpoint design and maintain clean, well-versioned interfaces
• Lead payments and calendar integrations with Stripe and Google Calendar, ensuring correctness of money and bookings
• Design resilient asynchronous workflows with Celery jobs and webhook handlers that are idempotent and retry-safe
• Profile slow queries, add indexes, and ensure async paths are non-blocking to maintain performance and reliability
• Use raw SQL or tune SQLAlchemy for transactions, locking, and safe migrations against production data
• Integrate and maintain third-party SDKs including Stripe, Google Calendar, Twilio, Firebase, and Cloudflare R2
• Occasionally contribute to client apps (React Native / React.js) for integration glue
• Maintain codebase health with type checking, Clean Architecture boundaries, reusable use cases, and sensible domain modeling