Junior Software Development Engineer - Backend, Communications at OfferUp

Picture a marketplace where neighbors connect in seconds, where a quick photo on a phone can turn an unused item into someone else’s new favorite. That’s the world OfferUp has built since 2011, now serving communities across the United States and reaching more than one in five adults. Behind every message that sparks a local transaction sits the Communications team, the group that keeps chat and notifications running smoothly so buyers and sellers can find each other with ease.

The opportunity

We’re looking for a backend engineer who will help shape the systems that power those conversations. You’ll join a team that owns both chat and notifications from end to end, giving you the chance to influence how millions of users stay connected. Because this role sits at the heart of our product, your decisions will directly affect the daily experience of people buying and selling in their own neighborhoods. The position is fully remote and open to candidates located outside the United States.

A day in the life

• You might start the morning reviewing metrics from a recent chat feature rollout, then pair with a product manager to sketch the next improvement based on what the data shows.
• Midday could find you refactoring a legacy notification service, weighing whether to rebuild or simply replace parts of the system while keeping uptime high for our users.
• In the afternoon you might jump on a cross-team call to share a new pattern that reduced latency, then lend a hand to a teammate who’s debugging a tricky microservice issue before wrapping up with a light on-call check-in.

Who you are

You bring at least three years of professional software engineering experience, including at least one year focused on web services. You write clean, well-tested code in Java, Python, Scala, Golang, or another modern language, and you’re comfortable designing object-oriented systems built on microservices. A bachelor’s or master’s degree in computer science or a related field supports your technical foundation. Bonus points if you’ve worked with chat platforms, message queues, AWS, or large-scale cloud infrastructure. Above all, you thrive when you can take full ownership of a project and deliver results in a fast-moving environment.

Why you'll love it here

You’ll enjoy the freedom of remote work and the satisfaction of building tools that millions of people rely on every day. Our engineering culture values collaboration, continuous improvement, and the chance to mentor others while growing your own skills. We also partner with nearly two thousand local law enforcement agencies to keep our marketplace trustworthy, so the impact of your work reaches beyond code into the communities we serve.