What are the responsibilities and job description for the Senior Backend Engineer (Product-Focused) position at FitNext Co.?
Senior Backend Engineer (Product-Focused)Location: San Francisco, CA (Onsite)Salary Range: $180,000 $230,000Company Size: Early-stage startup (1150 employees)About the RoleWe are looking for a Senior Backend Engineer who is deeply product-focused and excited to work in a fast-growing startup environment. You will collaborate closely with executive leadership and play a key role in shaping both the technical foundation and the future direction of the product.This role is ideal for engineers who enjoy ownership, ambiguity, and building from the ground up. Candidates coming exclusively from very large, highly layered organizations may find this environment less aligned.What You Will DoCollaborate closely with the CTO and CEO on strategic technical decisions and product direction.Design, develop, and optimize backend services, APIs, and real-time data processing systems.Implement and continuously improve in-house AI-driven systems, including large language modelpowered features.Lead projects end-to-end, from initial concept through production deployment, with a strong focus on scalability and reliability.Work directly with users to gather feedback, understand pain points, and iterate on the core product.Take ownership of backend architecture while maintaining a strong product mindset.What We're Looking For6 years of software engineering experience building production-grade backend systems.Strong proficiency with Python and Django, including building and maintaining robust APIs.Extensive experience with SQL databases, preferably PostgreSQL.Hands-on experience deploying and operating services on AWS.A product-oriented mindset with comfort operating in a startup environment.Ability to work autonomously, make technical decisions, and move quickly.Bonus PointsExperience with WebRTC.Experience with real-time data streaming or event-driven architectures.Familiarity with AI/ML infrastructure or deploying LLM-based systems.Interview ProcessTechnical Coding Interview (45 minutes)Live coding session working with a CSV file in the language of your choice.You should have a local environment ready to run code.Screen sharing required.Please disable any AI assistance tools in your IDE.System Design InterviewOnsite InterviewWhy JoinHigh-impact role with real ownership and visibility.Opportunity to help shape a new category of AI-powered technology.Small, collaborative team with a strong product and engineering culture.Competitive compensation and meaningful influence on product direction.
Salary : $180,000 - $230,000