Senior Software Engineer, Backend

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

Benefits offered by this job

Equity compensation

Flexible interview accommodations

Job summary

Duolingo, based in New York, is hiring a backend engineer to build and operate reliable, scalable systems powering our learner experiences. You’ll join the team responsible for core infrastructure and the Ads/Score/Observability pillars, collaborating with product, design, data science, ML, and ops to ship high-quality services.

Candidates should have a CS degree and strong fundamentals in data structures, algorithms, and software design, with experience in Java, Python or Kotlin and databases.

Qualifications

• Bachelor’s degree in CS or related field.
• Strong data structures, algorithms and software design.
• Experience programming in Java, Python or Kotlin.
• Solid understanding of database technologies.
• Experience building high-traffic APIs on public clouds.
• Experience with observability tools such as OpenTelemetry, Grafana, Prometheus or DataDog.

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

Databases

Cloud experience

OpenTelemetry

Grafana

Prometheus

DataDog

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:

Duolingo Score

Duolingo Score is how we reflect a learner's real language proficiency back to them. As the team lead / backend engineer on this small, high-impact team, you'll help make learners care about their score as much as they care about their streak. You'll partner closely with the Score Pillar's 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.

Time Spent Learning

The Time Spent Learning team is dedicated to motivating learners to spend more time engaging meaningfully with the Duolingo app. Our mission is to grow genuine, sustained learning time by designing and iterating on the mechanics that motivate consistent, high-effort practice so learners make real progress toward fluency each day. As a small, cross‑functional team of product, design, and engineering, we own a metric that shapes learning outcomes for millions of users and get to shape the Duolingo experience.

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.

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, you'll build instrumentation frameworks, deploy telemetry infrastructure, design dashboards, and connect signals to catch issues before they impact learners. We're looking for engineers passionate about developer experience and reliability.

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

Accommodations

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.

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