Senior/Software Engineer (Backend)

• 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
• 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
• 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

Benefits

• Medical, dental, and vision for employees as well as eligible partners and dependents
• Mental health benefits such as therapy sessions and coaching to support you to be your best self
• Fertility benefits to support your family planning journey
• Fully paid parental and adoption leave
• Fully paid subscription to Care.com and paid backup days for dependents and your fur family
• 401(k) with generous match and immediate vesting
• 20 days of paid time off, with two additional weeks off for winter break
• First-time home buyer bonus (in Pittsburgh)
• Competitive salaries and equity
• Yearly stipend for professional development
• Transportation reimbursement for however you get to work
• Lunch prepared daily by our in-house chefs
• Annual international retreat for all full-time employees
• Monthly events celebrating our team and their amazing work
• On-site gym and massages
• Game room for taking brain breaks

• 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
• Solid understanding of one or more database technologies
• A Bachelor’s degree in Computer Science or a related technical field
• Experience programming in Java, Python, or Kotlin
• Strong competencies in data structures, algorithms, and software design
• Industry experience building high-traffic APIs using public cloud providers
• Experience with industry observability technology, such as OpenTelemetry, Grafana, Prometheus, or DataDog