Fullstack Engineer

Scion Staffing, Inc.; San Francisco (CA); On-site; USD 160,000 - 180,000; Full time

Benefits offered by this job

Own products end-to-end with meaning

Work with enterprise customers

Grow with experienced engineers

Job summary

Scion Staffing, Inc. is representing an AI infrastructure startup in San Francisco seeking a backend-oriented full-stack engineer to own features end-to-end and help scale enterprise-grade infrastructure powering AI-driven applications.

In this role you will design and own complex, multi-tenant backend systems, build reliable external integrations, and ensure services are scalable, observable, and resilient in production.

Qualifications

• 3–6+ years building and operating production software.
• Strong backend skills with the ability to ship across the full stack.
• Production TypeScript and Node.js or Bun.

Responsibilities

• Build the backend systems powering the agent-evaluation and continuous-improvement platform.
• Improve the data models behind evaluation datasets, experiment runs, agent traces, knowledge versions, findings, and customer-defined quality criteria.
• Own enterprise integrations across their full lifecycle: auth, OAuth, webhooks, incremental syncs, backfills, rate limits, schema changes, retries, monitoring, and production support.
• Own features from technical design and implementation through deployment, monitoring, customer feedback, and iteration.
• Work directly with customers when needed — understand their systems, diagnose failures, and turn one-off requirements into reusable product capabilities.

Skills

Backend development

Node.js/TypeScript

PostgreSQL

Observability

Distributed systems

Tools

Redis

OAuth

Webhooks

Job queues

Job description

Scion Technology has been engaged to conduct a search for an experienced Fullstack Engineer for our client, an AI infrastructure startup company. This is a full-time position based in San Francisco, CA.

POSITION OVERVIEW

Our client is seeking a backend-learning full-stack engineer to own features end-to-end. Will help build and scale enterprise-grade infrastructure powering AI-driven applications. In this role you will design and own complex, multi-tenant backend system, develop reliable integrations with external platforms, and ensure services remain scalable, observable and resilient in production.

PERKS

• Own products end-to-end with meaningful influence over architecture, technical direction, and customer outcomes.
• Work directly with enterprise customers, turning complex real-world challenges into scalable product capabilities.
• Accelerate your growth by collaborating closely with experienced engineers in a fast-paced, high accountability environment.

RESPONSIBILITIES

• Build the backend systems powering the agent-evaluation and continuous-improvement platform.
• Improve the data models behind evaluation datasets, experiment runs, agent traces, - knowledge versions, findings, and customer-defined quality criteria.
• Own enterprise integrations across their full lifecycle: auth, OAuth, webhooks, incremental syncs, backfills, rate limits, schema changes, retries, monitoring, and production support.
• Own features from technical design and implementation through deployment, monitoring, customer feedback, and iteration.
• Work directly with customers when needed — understand their systems, diagnose failures, and turn one-off requirements into reusable product capabilities.

QUALIFICATIONS

• 3–6+ years building and operating production software.
• Strong backend skills with the ability to ship across the full stack.
• Production TypeScript and Node.js or Bun.
• Strong PostgreSQL; experience with Redis, job queues, background workers, or -workflow systems APIs, integrations, webhooks, and data pipelines for production-grade, multi-tenant software.
• Familiarity with observability, distributed systems, and agent-evaluation concepts.

COMPENSATION & BENEFITS

This direct hire position offers a salary of $160,000-180,000 annually. They offer a robust benefits package that includes comprehensive medical, dental, and vision coverage, along with additional perks.

Scion Staffing, Inc. is an equal opportunity employer and service provider and does not discriminate based on race, religion, gender, gender identity, national origin, citizenship status, sexual orientation, disability, political affiliation or belief, or any other protected class. We are committed to the principles of Equal Opportunity Employment and are dedicated to making employment decisions based on merit and value, for ourselves, our client companies, and the candidates we represent. For opportunities located in a region that have enacted fair chance, arrest or conviction-based employment ordinances, Scion Staffing proactively follows the enacted guidance and considers for employment all qualified applications with arrest and conviction records. We engage in socially conscious business practices and believe that diverse, inclusive, and non-biased talent and recruitment processes are foundational to the success of Scion as well as every client organization with whom we partner.