Full Stack Product Engineer (Node.js / React)

Mastermind.com; Scottsdale (AZ); On-site; USD 110,000 - 150,000; Full time

Job summary

Mastermind.com, based in Scottsdale, is seeking a mid-level Full Stack Product Engineer to join AI Advantage. You will own end-to-end features in a lean, high-ownership team, shipping in two-week sprints on a 70/30 backend/frontend split.

We require 4–6 years building production full stack apps, deep experience with Node.js/Express, MySQL on the backend, and React/Next.js/TypeScript/Tailwind on the frontend. This is an on-site, full-time role with US work authorization required.

Qualifications

• 4 to 6 years building production full stack applications inside a professional engineering team with code review.
• Experience with Next.js, React, TypeScript, and Tailwind.
• Strong ownership of both backend and frontend components.

Responsibilities

• Own the Customer Service Admin Suite end to end in production.
• Develop the Circle member experience (login, billing, account management).
• Maintain and improve the affiliate system to drive growth.
• Ship features every sprint through peer-reviewed pull requests.

Skills

Full stack ownership

Backend & frontend ownership

Production experience

Tools

Node.js

Express

MySQL

React

Next.js

TypeScript

Tailwind

Job description

Full Stack Product Engineer at AI Advantage / Mastermind.com

Location: Scottsdale, AZ, 100% on-site (not open to remote)

Work Structure: Full-time, W2

Eligibility: This role requires US work authorization without sponsorship, now or in the future (US citizens and green card holders).

Tech Stack: Our stack is Node.js and Express with MySQL on the backend, and React, Next.js, TypeScript, and Tailwind on the frontend.

We are looking for engineers whose recent production work is in our stack, not adjacent ones (Java, .NET, or Python-primary backends are not a fit).

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What This Role Is

This is a hands-on, mid-level full stack seat, not a lead role. Our team has rebuilt the platform on a clean, modern stack, so you inherit ownership, not years of tech debt.

• We're looking for five or more years owning both a production backend and the front end that consumes it; total career length neither qualifies nor disqualifies.
• You will own your work end to end on a lean senior team that ships in two-week sprints.
• Roughly 70% backend and systems, 30% front-end, with full code ownership.
• You will be building the tooling that keeps a large education platform running for real customers
• This is tooling and integration work with real leverage, not ticket-shuffling.
• This a pure build seat, pointed where it creates the most value.
• We are looking for an engineer who is organized and autonomous, ships clean through peer review, and genuinely rolls with change when priorities pivot fast.

What This Role Is Not

• Not a lead or management seat. You architect and ship, not run a team or defend a roadmap in meetings.
• Not a DevOps or platform-ops seat. No pagers, no babysitting deploys, so you spend your time building instead of firefighting.
• Not a solo builder's gig. If your entire background is personal projects with no professional team or code review, this is not a fit.
• Not an "AI writes it, I ship it" role. We want engineers who make sure what AI gives them actually works, not people who hand it off unchecked.
• Build a unified admin panel that lets a non-technical customer team fix accounts end to end in one click
• Own the plumbing that carries the whole company from point of sale into Circle
• Move work from to-do to done with clean hygiene and no one chasing you
• Own your own QA and ship through peer-reviewed pull requests, never work thrown over a wall
• Say "I don't think this is fully thought through, let's talk it through" before you write a line of code
• Set down yesterday's work for today's when priorities shift, without getting precious about it

...then we want to talk to you.

What You'll Own

Customer Service Admin Suite (Primary)

• The unified admin panel that lets Customer Service take a client end to end: one-click account, billing, and login fixes across one tool instead of five.
• This is the highest-leverage surface you will build, and what it can do keeps expanding.

Member Experience (Ongoing)

• The Circle member experience (login, billing, account management, lead flows) and the plumbing that connects our commerce stack to it, running smoothly end to end.

Affiliate System (Ongoing)

• Maintain, extend, and improve the affiliate system that drives growth.

How You Ship (Every Sprint)

• Own your work all the way to production: validate it yourself, walk a reviewer through your test cases, and ship through peer review.
• Keep clean progress and surface blockers early.

What We're Looking For

Requirements

• 4 to 6 years building production full stack applications inside a professional engineering team with code review
• Front-end: Next.js, React, TypeScript, Tailwind, iframes
• Cloud and hosting: Heroku and GCP
• Collaborative problem solving: you think fast with the team and pressure-test the plan before building, no rogue players
• Real AI fluency: you use AI as a craftsman's tool and make sure what it produces actually works
• US citizens and green card holders only. No visa sponsorship.

Strong Differentiators

• AI coding tools used well (Claude Code, Cursor), with the judgment to verify and own the output
• n8n or workflow automation experience
• Based in Scottsdale or Greater Phoenix
• 1 to 2 prior roles of roughly two years each, ownership. No job hopping

The Core Skill: Change Resilience

• Priorities here can pivot fast, and sometimes weeks of work get shelved the same day. Everyone says they are fine with that. Almost nobody is.
• The engineers who thrive treat a scrapped project as a redirect, not a loss. If that is genuinely how you are wired, you will do your best work here.