Senior/Software Engineer II, Backend

Our mission

at Duolingo is to develop the best education in the world and make it universally available. It’s a big mission, and that’s where you come in!

At Duolingo, you’ll join a team that cares about finding innovative solutions to complex technical problems , running countless experiments (300+ at a time!) with our massive user base to make data-driven decisions, and educating our users and employees alike

You’ll have limitless learning opportunities, mentorship and collaboration with world-class minds, and a variety of projects with large scopes — while doing work that’s both fun and meaningful.

Join our life-changing mission to develop education for our half a billion (and growing!) learners around the world.

We’re looking for backend engineers who have experience building and operating reliable, scalable systems Your background may be in product engineering, infrastructure, platform engineering, or a combination of these

What matters most is strong backend fundamentals, sound systems thinking, and the ability to take ownership of complex technical problems from design through production.

Below you can find more information about the team were hiring for: Duolingo Score:

Duolingo Score is how we reflect a learners real language proficiency back to them As a backend engineer on this small, high-impact team, youll help make learners care about their score as much as they care about their streak

Youll partner closely with the Score Pillars product and design team and our iOS and Android engineers, working on the systems that power score calculation, proficiency modeling, and how score surfaces across the app — including integrations with external platforms like LinkedIn, so learners can showcase their proficiency beyond Duolingo.

Ads

Duolingos Monetization pillar builds the systems that fund our mission — from subscription packaging and advertising to ML-powered personalization As a Backend Engineer on the Ads team, youll work on a product engineering team responsible for growing and scaling Duolingos ads business: high-quality ads that delight learners, fit seamlessly into the product experience, and meaningfully contribute to our bottom line

The team owns ad serving, mediation and demand, in-product ad formats and surfaces, and more Youll work cross-functionally with product, design, data science, machine learning, and ad operations.

Observability

The Observability team builds infrastructure and tools that give engineers confidence and clarity at Duolingo scale. We create monitoring, alerting, and debugging experiences that help teams ship faster and respond to incidents effectively. In this team, youll