Sr Backend Engineer - Distributed Systems

About Onfire Health

Onfire Health is an early-stage startup committed to making functional medicine and longevity care accessible and affordable for all. Engineering is central to our offering, as we are building a platform that incorporates multiple revenue channels and agentic payments management.

Our core platform is a payments and group-buying membership which allows members to fund their out-of-pocket health expenses with zero-interest using their savings plan. It leverages group-negotiated, discounted services using pre-planned savings instead of relying on expensive consumer debt.

What You'll Do

• Design and build robust RESTful APIs and microservices using Python and FastAPI
• Architect event-driven systems using Kafka for real-time data streaming and processing
• Implement authentication and authorization flows using Auth0 and modern security best practices
• Build and optimize PostgreSQL databases for performance, scalability, and reliability
• Deploy and manage services on GCP and AWS with focus on high availability and fault tolerance
• Design distributed systems that handle failures gracefully and scale horizontally
• Act as a tech lead: break down complex projects into manageable tasks and guide junior engineers
• Mentor and develop junior engineers: conduct code reviews, provide technical guidance, and help them grow
• Write clean, testable, and maintainable code with comprehensive documentation
• Collaborate with frontend engineers, product managers, and designers to ship features quickly
• Monitor system performance, troubleshoot issues, and optimize bottlenecks
• Drive technical decisions and contribute to architecture and engineering standards
• Participate in on-call rotation and lead incident response when needed

Required Qualifications

• 8+ years of backend engineering experience building production systems at scale
• Proven ability to lead technical projects and mentor junior engineers
• Experience breaking down complex projects into executable tasks and managing technical delivery
• Expert-level Python proficiency with deep understanding of async/await patterns and concurrency
• Hands-on experience with FastAPI or similar modern Python web frameworks (Flask, Django)
• Strong understanding of distributed systems concepts: consistency, availability, partition tolerance, and CAP theorem
• Extensive experience building and consuming RESTful APIs and event-driven architectures
• Proficiency with Kafka or similar message brokers (RabbitMQ, AWS SQS, Google Pub/Sub)
• Expert PostgreSQL skills including query optimization, indexing, data modeling, and performance tuning
• Experience with cloud platforms (GCP and/or AWS) and containerization (Docker, Kubernetes)
• Deep knowledge of authentication/authorization systems (Auth0, OAuth 2.0, JWT)
• Strong understanding of CI/CD pipelines and infrastructure as code
• Track record of architecting and shipping reliable, well-tested systems in fast-paced environments
• Excellent communication skills and ability to collaborate across teams

Tech Stack

Nice to Have

• Experience with healthcare systems (HIPAA compliance, HL7/FHIR standards, EHR integrations)
• Experience with payment systems and financial infrastructure (PCI-DSS compliance, Stripe, payment processing)
• Knowledge of service mesh architectures (Istio, Linkerd)
• Experience with distributed tracing and observability (Jaeger, OpenTelemetry)
• Familiarity with database replication, sharding, and partition strategies
• Understanding of rate limiting, circuit breakers, and resilience patterns
• Knowledge of event sourcing and CQRS patterns
• Experience with performance testing and chaos engineering

Compensation

As an early-stage startup, we offer a competitive and performance-driven total compensation package that includes a significant equity component. The specific salary and stock option grant will be highly competitive and commensurate with your experience, skill level, and the impact you bring to the role.