Full Stack Developer (Junior/Intermediate)

Full Stack Developer
Junior / Intermediate

About Reactiv

Reactiv is an AI-powered platform that helps Shopify merchants build beautifully branded,
high-converting mobile apps without the usual complexity. At the core of what we do is
Reactiv Clips, a feature that removes the need for app downloads so brands can deliver
fully customized app experiences instantly and without friction. By lowering the barrier to
great mobile experiences, we're building the future of mobile commerce, and we're
growing our engineering team to help shape what comes next.

About the Role

We're looking for a Junior to Intermediate Full Stack Developer to help build and improve
the platform our merchants rely on every day, from the dashboard they use to design and
manage their apps to the e-commerce APIs that power them. You'll ship real features
from early on, with support and mentorship from our engineering team to help you grow.
Most of your work will be in TypeScript across React on the frontend and Node.js on the
backend, with the chance to go deeper on whichever side excites you most. This is a
hands-on role for someone earlier in their career who wants to develop into a strong full
stack engineer in a collaborative, hybrid environment. You don't need to check every box
below; if you're solid on the fundamentals and eager to learn the rest, we want to hear
from you.

What You'll Do

● Build and maintain features across our merchant dashboard React and
TypeScript) and our backend services and e-commerce APIs Node.js and
TypeScript).
● Write and consume RESTful and GraphQL APIs that connect our frontend
experiences to server-side functionality.
● Work with relational databases such as Postgres: designing simple schemas,
writing queries, and learning optimization along the way.
● Contribute to our Shopify integrations that keep merchant data in sync.
● Collaborate with product, design, and other engineers to define, design, and ship
new features.
● Help keep the platform fast and reliable by improving performance and
responsiveness on both sides of the stack.
● Take part in code reviews, both giving and receiving feedback, as part of how we
maintain quality.
● Troubleshoot and fix issues across the stack to improve the experience for
merchants.

What We're Looking For

Required

● Working knowledge of React and a solid grasp of its core concepts.
● Some experience building backend services or APIs with Node.js.
● Comfortable writing TypeScript, or strong JavaScript with a willingness to pick up
TypeScript quickly.
● An understanding of how frontend and backend talk to each other: RESTful APIs,
requests, responses, and error handling.
● Familiarity with relational databases such as Postgres or MySQL.
● Strong problem-solving instincts and eagerness to learn in a fast-moving,
collaborative team.
● Roughly 2 to 4 years of experience building web applications, or equivalent project
and portfolio work.

Nice to Have

● Experience with GraphQL.
● Familiarity with the Shopify ecosystem, or an interest in ecommerce.
● Exposure to AWS services Lambda, S3, RDS, DynamoDB or other cloud
infrastructure.
● Experience with a React framework such as Next.js or React Router (formerly
Remix).
● Experience writing automated tests Jest, React Testing Library, or integration
tests).
● Understanding of authorization concepts such as OAuth and JSON Web Tokens.
● Familiarity with CI/CD practices.
● Exposure to React Native, or interest in contributing to mobile.

Why Join Us

● Mentorship and growth: You'll have regular code review, pairing, and support from
experienced engineers, with a clear path from junior to intermediate and beyond.
● Level up with AI We're constantly exploring how AI can make us better engineers,
and you'll have real freedom to experiment with cutting-edge tools rather than wait
for permission. It's a fast way to grow.
● Real impact: The features you build are used by merchants running their
businesses around the world.
● Hybrid work environment: We believe in a hybrid model to create opportunities for
intentional in-person collaboration (and mentorship) while balancing that with the
deep focus time that comes from working remotely. You'll join the team in our
Toronto office 2 to 3 days a week with the flexibility to work remotely the rest of
the time.
● You're an owner: Every engineer at Reactiv gets equity, so you share in the upside
you help create. You're not just building the product, you own a piece of it.
● Benefits from day one: Extended health and dental coverage that kicks in the day
you start, no waiting period.
● Unlimited PTO We take time off seriously here. Most of our engineers take around
three weeks a year, and more when they need it, and we actively encourage
stepping away to rest and protect against burnout.

How to Apply

Send your resume and any project links, portfolio, or GitHub profile to careers@reactiv.ai.
A cover letter is optional, but we'd welcome a short note on why this role interests you.