Duolingo tech stack
Duolingo builds mostly with Python, Kotlin, Java, SQL. Its stack also includes AWS, Datadog, OpenTelemetry, MySQL. Python is named in 15 of the 49 job postings Duolingo published in the last 12 months (31%). Counted by Alion from the job postings of Duolingo, updated Sep 29, 2026.
What programming languages does Duolingo use?
Python is named in 31% of job postings at Duolingo, followed by Kotlin (24%), Java (16%), SQL (14%).
What frameworks and libraries does Duolingo use?
OpenTelemetry is named in 6% of job postings at Duolingo, followed by Jetpack Compose (4%), StoreKit (2%).
What databases does Duolingo use?
MySQL is named in 4% of job postings at Duolingo, followed by PostgreSQL (4%).
MySQL
2 4%
PostgreSQL
2 4%
What cloud and platforms does Duolingo use?
AWS is named in 6% of job postings at Duolingo, followed by Datadog (6%), Grafana (6%), Kubernetes (6%).
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What developer tools does Duolingo use?
Prometheus is named in 6% of job postings at Duolingo, followed by Terraform (6%), Cursor (4%), Docker (4%).
Prometheus
3 6%
Terraform
3 6%
Cursor
2 4%
Docker
2 4%
ArgoCD
1 2%
CloudFormation
1 2%
Google Play Billing
1 2%
Jenkins
1 2%
What AI and ML technologies does Duolingo use?
LLM is named in 8% of job postings at Duolingo, followed by ChatGPT (6%), GPT-4 (2%).
Which engineering practices does Duolingo ask for?
Machine Learning is named in 37% of job postings at Duolingo, followed by A/B Testing (14%), Fine-tuning (8%), Platform Engineering (8%).
Fine-tuning
4 8%
Platform Engineering
4 8%
AI Agents
3 6%
CI/CD
3 6%
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What other technologies does Duolingo use?
Kotlin Coroutines is named in 4% of job postings at Duolingo.
Kotlin Coroutines
2 4%
What does each Duolingo team work with?
The technologies each team's postings require most often, with the number of postings that require them.
Mobile
11 postingsData Science
6 postingsBackend
5 postingsHow does your stack fit Duolingo?
How is the Duolingo stack changing?
Read from the dates of the postings themselves: a technology is new when the first posting that names it appeared in the last six months, rising or falling when its share of postings moved between the last two quarters.
How modern is the Duolingo stack?
Duolingo scores 90 out of 100 (Cutting-edge). The score averages how current each technology in the stack is and adds weight for AI adoption. AI technologies in the stack: 3; legacy ones: 0.
Companies with a stack like Duolingo
Questions about the Duolingo tech stack
What programming languages does Duolingo use?
The languages named in Duolingo job postings are Python (31%), Kotlin (24%), Java (16%), SQL (14%), Swift (14%), as a share of the 49 postings of the last 12 months.
Does Duolingo use OpenTelemetry?
Yes. OpenTelemetry is named in 3 of 49 job postings (6%) and required in 3 of them.
What cloud and platforms does Duolingo use?
The cloud and platforms named in Duolingo job postings are AWS (3), Datadog (3), Grafana (3) (postings in brackets).
What skills do you need for a Mobile job at Duolingo?
Mobile postings at Duolingo most often require Swift (6), Kotlin (5), iOS SDK (3), Jetpack Compose (2), out of 11 postings in the last 12 months.
Is the Duolingo tech stack changing?
Yes. Docker, MySQL, PostgreSQL, Kubernetes first appeared in Duolingo job postings in the last six months.
How modern is the Duolingo tech stack?
Duolingo scores 90 out of 100 (Cutting-edge). The score averages how current each technology in the stack is and adds weight for AI adoption. AI technologies in the stack: 3; legacy ones: 0.
How does Alion know the Duolingo tech stack?
Alion reads every job posting Duolingo publishes and tags the technologies each one names. The figures on this page count the 49 postings of the last 12 months and were updated on Sep 29, 2026.
Method and citation
Alion reads every job posting the company publishes and tags the technologies each one names. Shares count the postings of the last 12 months, open and closed; the company's own products are counted apart. How we count
Alion, "Duolingo tech stack: 53 technologies from 49 job postings", as of Sep 29, 2026. https://alion.io/company/duolingo-blog/technologies