Senior Android Engineer (Client Platform, Application Stability and Performance)

Duolingo; York and North Yorkshire; On-site; GBP 90,000 - 130,000; Full time

Benefits offered by this job

Medical coverage

Mental health support

Fertility benefits

Paid parental leave

Equity & salary

Job summary

Duolingo is seeking an Android engineer to own the stability and performance of the Android Learning app for millions of learners. You will lead architectural initiatives, evolve performance tooling, and serve as a bridge between Client Platform and product teams to ensure robust, scalable experiences.

You will mentor engineers, tackle tough performance challenges, and contribute to a culture of engineering excellence with a focus on memory, startup time, and smooth user experiences across

Qualifications

• Strong Kotlin skills and deep familiarity with coroutines, Jetpack Compose, and modern architecture patterns.
• Experience optimizing startup time, memory, and network usage for low-memory devices.
• Strong problem-solving skills and a passion for tackling difficult challenges.
• Experience identifying root causes and resolving ANRs, memory leaks, dropped frames, and complex crashes.

Responsibilities

• Own the stability and performance of the Duolingo Android app for millions of learners.
• Lead architectural initiatives to fix the slowest parts of the app, from startup to critical learning flows.
• Own and evolve performance tooling with tracing, benchmarking, and automated regression detection.
• Serve as a bridge between Client Platform and Product feature teams, helping them act on performance data.
• Foster a culture of engineering excellence around performance and mentor engineers of all experience levels.

Skills

Kotlin

Coroutines

Jetpack Compose

Architecture patterns

Startup optimization

ANR debugging

Tools

Sentry

Perfetto

AndroidX Tracing Library

Android Vitals

Job description

• As an Android engineer on our Application Stability and Performance team you’ll own the stability and performance of the Duolingo Android Learning app for millions of learners
• This team builds the tooling other engineers depend on to keep the app performant like AI agent driven crash and memory analysis, coroutine system tracing, and Macrobenchmark suites that catch regressions before they ship
• You’ll also own the performance metrics that feed into our experiment analyses and help ensure hundreds of concurrent experiments surface any performance issues or regressions
• Lead architectural initiatives to fix the slowest parts of the app, from startup to critical learning flows
• Own and evolve our performance tooling with tracing, benchmarking, and automated regression detection
• Serve as a bridge between Client Platform and Product feature teams, helping them understand and act on the performance data we provide
• Foster a culture of engineering excellence around performance and mentor engineers of all experience levels

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

Strong Kotlin skills and deep familiarity with coroutines, Jetpack Compose, and modern architecture patternsExperience optimizing startup time, memory, and network usage for low-memory devicesStrong problem-solving skills and a passion for tackling difficult challengesExperience identifying the root cause and resolving ANRs, memory leaks, dropped frames, and complex crashesWorked on and shipped large scale Android applicationsExperience with crash observability tooling like Sentry and Android VitalsExpertise in Android tracing tooling like the AndroidX Tracing Library and Perfetto