Senior Full Stack Engineer - Autonomous Growth Marketing Platform

Job Title: Full Stack Engineer, Product & User Platform

Location: San Francisco, CA (Hybrid)

Team: Engineering

Partner: A pioneering AI company building an autonomous operator for growth marketing.

Underdog.io is a modern recruitment platform. One of our growing hiring partners is looking to hire a Sr Full Stack Engineer.

About Our Hiring Partner

Our hiring partner is engineering a paradigm shift in digital growth by building an AI Operator that autonomously manages advertising spend with the quantitative rigor of institutional trading. Their platform delivers transformative efficiency gains, replacing manual agency workflows with algorithmic precision. Already managing critical budgets for leading global brands, they are on a definitive path to scaling billions in autonomous ad volume. As an early-stage San Francisco team, they are assembling foundational talent to build not just the intelligence, but the critical interfaces that foster human trust in autonomous systems.

Why This is a Foundational Opportunity

• Build the Trust Layer: Architect the primary interface where executives interact with an autonomous system, directly translating complex AI decisions into actionable insights and strategic control.
• Lead the Product Evolution: Own the full-stack development that transitions the platform from a service to a self-serve product, empowering brands to manage their P&L with confidence.
• Define the Human-Machine Interface: Pioneer intuitive patterns for explainable AI, real-time monitoring, and strategic guardrails within a high-stakes financial context.
• SF-Based Product Leadership: Join a concentrated team in San Francisco in one of the most user-centric and impactful San Francisco startup jobs, shaping the product experience for a category-defining platform.

About the Role

We are seeking a Full Stack Engineer to build the cockpit for our autonomous system. While our backend engines run the math, you will build the interface that builds trust. You will own the entire layer where humans interact with the machine, creating not static dashboards, but a dynamic Command Center.

This role is about empowering CFOs and Growth Leaders to monitor live experiments, understand the rationale behind every AI decision, and inject strategic guardrails. You will lead the technical development that transforms the user experience from observation to collaboration.

What You'll Do

• Build the Command Center: Architect and develop the primary web interface for monitoring performance. This includes building real-time dashboards for live experiments, comprehensive audit logs, and admin panels for configuring safety parameters and strategic rules.
• Engineer the Slack Operating System: Design and build deep Slack integrations that serve as a primary user interface, creating workflows for anomaly alerts, push notifications, and interactive approval flows for high-stakes decisions.
• Develop Generative Analytics: Integrate LLMs to power on-demand, conversational analytics. Build interfaces where users can ask natural language questions and receive instant, generated charts, visualizations, and experiment summaries.
• Design for Explainability: Create UI components and data visualizations that clearly explain AI decision-making. Translate complex causal data into intuitive "Rationale" displays that bridge the gap between algorithmic output and human strategic understanding.

Who You Are

• A Product-Minded Engineer: You have 4+ years of experience building full-stack web applications. You care deeply about the user journey and possess an intuitive sense for presenting complex data simply and effectively.
• Modern Stack Expert: You are fluent in React and TypeScript on the frontend, and have strong backend skills in Python or Node.js. You build fast, responsive, and reliable interfaces.
• A Communicator of Complexity: You excel at progressive disclosure and information architecture, knowing how to tailor the presentation of data for different user personas, from executives to analysts.
• High-Agency & Trust-Obsessed: You proactively identify and solve UX friction. You view the product interface as the primary engine for building user confidence and trust in an autonomous system.

Bonus Points

• Slack App Development: Experience building complex, interactive Slack applications using the Bolt framework or similar platforms.
• LLM Integration Experience: Hands-on experience designing frontend patterns for streaming text and structured data from LLMs to create low-latency, responsive AI experiences.
• Design Systems: Experience building or maintaining a component library or design system.
• Zero-to-One Product Experience: A background in early-stage startups, building products from the ground up and iterating rapidly based on user feedback.

Compensation & Benefits

This role offers a competitive package designed for a product-critical, early engineering hire.

• Salary: Up to $275,000
• Equity: A significant early-stage equity package.
• Relocation: Support for candidates moving to the Bay Area.
• Daily Meals: Provided lunch and optional dinner.
• Comprehensive Benefits: Full health, dental, and vision coverage, alongside an unlimited PTO policy.

Apply Now

If you are a full-stack engineer who is passionate about building intuitive, powerful interfaces that translate complex systems into user confidence and control, we encourage you to apply. This is a defining San Francisco startup job for those who want to build the critical trust layer for the future of autonomous business operations.