# Sr Full Stack Engineer

**Company:** [Haus](https://hotfix.jobs/companies/haus)
**Location:** San Francisco, CA, Seattle, WA, New York, NY
**Role:** Fullstack Engineering
**Salary:** $200k – $220k/yr
**Experience:** 5+ years
**Skills:** Python, React, Flask, Sqlalchemy, GCP, MySQL, Postgres, REST APIs, Database Migrations, Data Visualization
**Posted:** 2026-06-12

> Build and evolve full-stack systems powering causal inference marketing experiments. Own features across Python/Flask APIs, React frontends, and data integrations with ad platforms.

## Job Description

## What you’ll do
- Own features end-to-end: from API design and database migrations through React UI and data visualization, all the way to monitoring and on-call support
- Build and harden integrations with third-party ad platforms (Meta, Google, TikTok) — design for reliability across APIs you don’t control
- Evolve and modernize a production Flask + React application that serves hundreds of customers — improve architecture incrementally while shipping continuously
- Design and build data-rich UIs: charts, dashboards, and interactive tools that help marketers understand complex experimental results
- Collaborate closely with scientists and data engineers to translate statistical outputs into product experiences customers can act on
- Use AI development tools as part of your daily workflow to accelerate delivery, explore solutions, and raise the ceiling on what you can ship
- Participate in on-call rotation and own the operational health of the systems you build
- Review code across the team and help set the bar for quality, clarity, and maintainability

## Qualifications
- 5–10+ years of experience building and shipping production web applications and APIs
- Strong across the full stack: you can build a well-structured API endpoint, write a database migration, and implement the frontend that consumes it
- Proficiency in Python and React (or strong equivalents with willingness to ramp); experience with Flask, SQLAlchemy, or similar frameworks is a plus
- Experience working in and improving large, established codebases — you’ve navigated legacy systems, made pragmatic tradeoffs between refactoring and shipping, and left things better than you found them
- Comfort with cloud-native environments (GCP preferred): you understand how to deploy, monitor, and operate services in production
- Experience with relational databases (MySQL/PostgreSQL) and data-heavy applications
- Track record of working effectively with AI development tools (Claude, Cursor, Copilot, or similar) — you’ve integrated them into your workflow and can articulate how they change the way you build software
- Strong product sense: you think about what customers need, not just what the ticket says
- Excellent communication skills — you can explain technical tradeoffs clearly and work effectively with scientists, product managers, and other engineers

## For Staff level
- Demonstrated ability to lead technical direction for a system or product area, making architectural decisions that hold up as the team and product scale
- Experience driving cross-team or cross-system initiatives — you’ve coordinated changes across multiple services or repositories and managed the sequencing
- A track record of mentoring other engineers and raising the technical bar of the team through code review, design guidance, and leading by example
- Comfort operating with ambiguity: you can take a loosely defined problem, break it down, build the plan, and drive it to completion without heavy oversight

## Bonus Points
- Earlier stage startup experience
- Experience with ad platform APIs (Meta Marketing API, Google Ads API)
- Experience with data visualization or experimentation platforms
- Experience with third-party data integrations and ETL workflows

## What We Offer
- Flexible PTO
- Equity
- Top of the line health, dental, and vision insurance
- WFH stipend
- Events & Offsites
- Free Lunch (SF, NYC, Seattle offices)
- New Parent Leave

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**Canonical:** https://hotfix.jobs/jobs/cb0c48bb-9685-4b13-a9cb-680158bc15b4