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 we're hiring for:

Ads:

• Duolingo's 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, you'll work on a product engineering team responsible for growing and scaling Duolingo's 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.
• You'll work cross-functionally with product, design, data science, machine learning, and ad operations.

AI Platform:

• As a member of the AI Tooling and Ecosystem Team, you will be responsible for developing and maintaining tools and services that power Duolingo's use of AI in the product.
• You will design systems for managing datasets, evaluating the performance of AI models, and building AI workflows.
• You will help shape how Duolingo builds features using AI, enabling teams to easily define quality metrics, combine human and AI feedback, and compare model performance across different use cases.

🧠 You will...

• Collaborate on software projects with product design and backend aspects
• Develop, release, and maintain backend services and/or infrastructure
• Lead individual project priorities, milestones, and ensure we're always shipping

✅ You have...

• A Bachelor's degree in Computer Science or a related technical field
• Strong competencies in data structures, algorithms, and software design
• Experience programming in Java, Python, or Kotlin
• Solid understanding of one or more database technologies

⭐ Exceptional candidates will have...

• Industry experience building high-traffic APIs using public cloud providers
• Experience with industry observability technology, such as OpenTelemetry, Grafana, Prometheus, or DataDog.

• The offered salary is dependent upon several factors, including work experience, skills, and internal peer comparisons.
• The posted range is subject to change in the future.
• For this role, base salary is supplemented by equity compensation.
• We encourage you to talk with your recruiter for more information related to compensation for this role!

Salary Range:

$182,800 — $247,300 USD

Benefits

Take a peek at how we care for our employees' holistic well-being with our benefits here .

We do not discriminate based upon race, religion, color, national origin, gender (including pregnancy, childbirth, or related medical conditions), sexual orientation, gender identity, gender expression, age, status as a protected veteran, status as an individual with a disability, or other applicable legally protected characteristics.

• Duolingo and our employees will never ask for your Social Security number, bank details, or passport info, and we'll never ask you to deposit a check, purchase equipment, or exchange money during the interview process.
• Real Duolingo employees always use an email that ends in @duolingo.com or @recruiting.duolingo.com.
• Stay alert and double-check these details before sharing any information.
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