Senior/Software Engineer II, Backend

Duolingo; New York (NY); On-site; USD 183,000 - 247,000; Full time

Job summary

Duolingo is seeking a Backend Engineer to design, build, and operate reliable, scalable systems across Ads and AI tooling teams. You’ll own substantial backend components, collaborate with product, design, data science, ML, and operations, and drive projects from design through production.

Ideal candidates have a CS degree, strong data structures/algorithms, and experience in Java, Python, or Kotlin, plus solid DB knowledge. Competitive salary range in USD is highlighted in the posting.

Qualifications

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

Responsibilities

• 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.

Skills

Java

Python

Kotlin

Data structures

Algorithms

Software design

Education

Bachelor's degree in Computer Science

Tools

OpenTelemetry

Grafana

Prometheus

Datadog

Job description

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.

• 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.

We will do everything we can within reason to make sure that your interview takes place in an environment that fairly and accurately assesses your skills. If you need assistance or accommodation, please contact [e-mail].

Equal Employment Opportunity: Duolingo is proud to be an Equal Employment Opportunity employer. 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.

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

AI in Hiring: Duolingo uses AI technology to assist in our hiring process. We want to be transparent about how we use this technology and your rights. We use Greenhouse Software's Talent Matching feature to assist with reviewing applications for the skills and experience we have decided are important for this role.

How it works:

• Talent Matching reviews your resume and responses to application questions to determine the extent to which your qualifications match the job requirements selected for this role. These requirements and their desired weighting are established by our recruiters in collaboration with hiring managers.
• All Talent Matching output is reviewed by our recruiting and hiring teams, who make the final decision on each application. Talent Matching does not automatically disposition any candidate or make hiring decisions.