Backend Engineer

Notes to applicants

• Start date: Feb 2026.
• Preffect does not sponsor work visas.
  You must be fully authorized to work in the US for your application to be considered.
• This is a hybrid role based in the San Francisco Bay Area.
   If you are not currently located in the San Francisco Bay Area, you are expected to relocate for this role.

About the Role

As a Backend Engineer at Preffect, you will own and deliver core API services, backend systems, and data processing pipelines that power our AI native Health & Wellness mobile experience, available on the App Store at

You will actively use AI powered development workflows to rapidly deliver high quality features. You will work closely with our product, ML, and frontend teams to build reliable, scalable, and maintainable backend features that deliver seamless user experiences.

This is a hands-on individual contributor (IC) role with high expectations of ownership. You will design, build, and ship production services while collaborating across the organization to accelerate product development velocity.

Responsibilities

Backend Development & API Ownership

• Design, build, and maintain RESTish APIs and microservices using Python.
• Implement backend services using Django or FastAPI.
• Own end-to-end API design including data modeling, versioning, and documentation.
• Ensure reliability, scalability, and observability for all backend systems.

Data Streaming & Processing

• Build and maintain data ingestion, streaming, and processing pipelines.
• Work with async tasks, background workers, and event-driven patterns.
• Partner with ML engineers to support model serving and data workflows.

Cross Functional Collaboration

• Partner with product, ML, and frontend teams to support feature development.
• Collaborate with engineering leadership to improve architecture and processes.
• Contribute to internal documentation, tooling, and engineering best practices.

Minimum Qualifications

5 to 8 years of professional backend engineering experience.

Strong proficiency in Python and Git workflows.

Production experience with at least one of: Django or FastAPI.

Experience building and maintaining RESTful or RESTish APIs.

Experience with data streaming, ingestion, or processing systems.

Proficiency with AI assisted coding tools such as Windsurf, GitHub Copilot, Cursor, or similar for daily development.

Ability to balance cutting edge automation with human engineering judgment to maximize velocity while ensuring robustness, reliability, and maintainability.

Ability to thrive in a fast moving startup environment.

Strong communication skills and collaborative mindset.

Preferred Qualifications

Experience with PostgreSQL.

Familiarity with Kubernetes.

Experience with microservice architectures.

Interest in Consumer Health & Wellness.

Compensation & Location

• Compensation: $170K annual salary, plus equity based on candidate experience and strength.
• Benefits: Health insurance with dental and vision, HSA / FSA, life insurance, 401(k).
• Location: Initially remote, but candidates must be based in the SF Bay Area for in person collaboration as needed.

Why Join Preffect

Preffect is building the future of personalized Health & Wellness through AI native experiences. We are privately funded with a robust runway, which empowers us to prioritize product quality, user impact, and long-term impact over short-term pressures or external constraints.

You will join an elite, execution-oriented team where your work directly influences how users interact with and benefit from Preffect. You will have meaningful ownership, autonomy, and the opportunity to deliver revolutionary features at scale, and shape critical backend systems that unlock rapid product innovation and elevate the entire engineering organization.

If you're excited by the intersection of innovative consumer technology, cutting edge applications of AI, and Health & Wellness, we'd love to hear from you

Apply today to help us build the future of personalized Health & Wellness at Preffect.