Senior Full-Stack Engineering

Senior Fullstack Engineer
Our client is a fast-moving marketing measurement and attribution technology company that empowers e-commerce brands to make smarter, data-driven advertising decisions. Their platform combines a robust Rails API, a modern React frontend, and a Python-powered data and ML infrastructure — all operating across a 20+ repository workspace where AI agents and engineers collaborate side by side to ship product at speed. They are a team that values engineering craft, architectural clarity, and a bias toward simplicity, and they are looking for senior engineers who raise the bar through code review, documentation, and thoughtful system design as much as through feature delivery.
The Senior Fullstack Engineer will own and elevate engineering quality across a multi-repo platform that spans a Rails API, React frontend, and Python data and ML services. This role sits at the intersection of backend architecture, frontend delivery, and data platform development, making it ideal for a polyglot engineer who is energized by ambiguity and cross-service complexity. The Senior Fullstack Engineer will also mentor fellow engineers, establish best practices, and help design agent-readable systems as AI-assisted development becomes a core part of how the team operates.
Fully Remote (Work from Home) | 9AM - 5PM EST
Backend Development

Design and ship production features on the Ruby on Rails API (or similar MVc), including authentication flows, background jobs via Sidekiq, and PostgreSQL schema design.
Maintain and improve API contracts using OpenAPI or JSON:API standards consumed by SPA frontends.
Frontend Development

Build and maintain React applications using hooks and modern state management patterns.
Work confidently with TypeScript, modern bundlers, and JS toolchains including Bun, Vite, and esbuild.
Python & Data Platform

Contribute to ETL pipelines, Snowflake transformations, and external API integrations.
Work with orchestration tools such as Dagster or Airflow to manage data workflows in production.
Partner with Data Science and ML Engineering teams to productionize models into reliable, observable inference services.
Infrastructure & DevOps

Maintain and improve container-based local development using Docker and Docker Compose.
Operate within an AWS environment (ECS Fargate, Lambda, EventBridge, S3) and support infrastructure managed via Terraform.
Own and improve CI/CD pipelines using GitHub Actions and drive pragmatic observability across services.
Establish and enforce engineering best practices across a 20+ repo workspace, covering testing strategy, CI/CD, observability, and code review standards.
Improve developer experience through local dev tooling, Makefile automation, and onboarding documentation.
Write clear specs, RFCs, and architecture docs — including agent-readable context files for AI coding agent workflows using tools like Claude Code or Cursor.
5+ years building production Ruby on Rails APIs (Rails 7+), with deep familiarity with ActiveRecord, Sidekiq, RSpec, JWT/auth flows, and PostgreSQL schema design.

• 5+ years building production React applications using hooks and modern state management patterns.
• TypeScript and modern JS toolchains including Bun, Vite, and esbuild.
• Production Python (3.11+) experience, ideally with Dagster, Airflow, or similar orchestration frameworks.
• Hands-on experience contributing to ETL pipelines, Snowflake transformations, and external API integrations.
• Experience with Docker, Docker Compose, and container-based local development workflows.
• Working knowledge of AWS services (ECS Fargate, Lambda, EventBridge, S3) and infrastructure-as-code via Terraform.
• Experience with CI/CD pipelines using GitHub Actions and a strong understanding of observability practices.
• Track record of writing technical specs, RFCs, or architecture documentation in a cross-team environment.

Strong architectural thinking across backend, frontend, and data systems — able to spot patterns and risks across services.
Comfortable operating autonomously in a multi-repo, fast-moving codebase alongside AI coding agents.
Strong opinions loosely held on testing strategy, dependency management, and incremental refactoring.
This is a rare opportunity for a polyglot senior engineer to have genuine architectural ownership across an entire product platform — not just one slice of the stack. You will work at the frontier of AI-assisted software development, shaping how engineers and AI agents collaborate in a production environment, while directly influencing the engineering culture and practices of a growing, technically ambitious team. The role offers a competitive base compensation of $4,000–$5,000 per month, full remote flexibility, and the chance to make a lasting mark on a platform that sits at the intersection of machine learning, marketing intelligence, and modern software engineering.
Application Process:
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