Leon tech stack
Leon builds mostly with Java, Kotlin, SQL, Python. Its stack also includes PostgreSQL, Apache Kafka, Kubernetes, Redis. PostgreSQL is named in 25 of the 27 job postings Leon published in the last 12 months (93%). Counted by Alion from the job postings of Leon, updated Nov 14, 2026.
What programming languages does Leon use?
Java is named in 74% of job postings at Leon, followed by Kotlin (52%), SQL (19%), Python (19%).
1C 
What frameworks and libraries does Leon use?
JUnit is named in 70% of job postings at Leon, followed by Mockito (52%), Spring Boot (52%), Spring Framework (52%).
JUnit
19 70%
Mockito
14 52%
Spring Boot
14 52%
Spring Framework
14 52%
Rest-Assured
5 19%
Selenium
5 19%
TestNG
5 19%
What databases does Leon use?
PostgreSQL is named in 93% of job postings at Leon, followed by Redis (81%), OpenSearch (30%), ClickHouse (7%).
What cloud and platforms does Leon use?
Apache Kafka is named in 85% of job postings at Leon, followed by Kubernetes (81%), Grafana (30%), RabbitMQ (22%).
Apache Kafka
23 85%
Kubernetes
22 81%
Grafana
8 30%
RabbitMQ
6 22%
Postman
5 19%
Debian
3 11%
GitLab CI
3 11%
Show all (16)
What developer tools does Leon use?
Docker is named in 74% of job postings at Leon, followed by TestRail (33%), Git (26%), Rest API (26%).
Docker
20 74%
TestRail
9 33%
Git
7 26%
Rest API
7 26%
Jenkins
6 22%
Keycloak
6 22%
Ansible
4 15%
Prometheus
4 15%
Show all (23)
Which engineering practices does Leon ask for?
CI/CD is named in 41% of job postings at Leon, followed by VLAN (11%), VPN (11%), Wi-Fi (11%).
Show all (11)
What does each Leon team work with?
The technologies each team's postings require most often, with the number of postings that require them.
Backend
14 postingsQA
8 postingsDevOps
3 postingsHow does your stack fit Leon?
How modern is the Leon stack?
Leon scores 66 out of 100 (Modern). The score averages how current each technology in the stack is and adds weight for AI adoption. AI technologies in the stack: 0; legacy ones: 0.
How common is the Leon stack in its industry?
Share of the 399 companies in the same industries, whose stack Alion knows, that use each technology.
What sets Leon apart
Companies with a stack like Leon
Questions about the Leon tech stack
What programming languages does Leon use?
The languages named in Leon job postings are Java (74%), Kotlin (52%), SQL (19%), Python (19%), 1C (4%), as a share of the 27 postings of the last 12 months.
Does Leon use JUnit?
Yes. JUnit is named in 19 of 27 job postings (70%) and required in 19 of them.
What cloud and platforms does Leon use?
The cloud and platforms named in Leon job postings are Apache Kafka (23), Kubernetes (22), Grafana (8) (postings in brackets).
What skills do you need for a Backend job at Leon?
Backend postings at Leon most often require Apache Kafka (14), Docker (14), JUnit (14), Java (14), out of 14 postings in the last 12 months.
Is the Leon tech stack changing?
No new technology has appeared in Leon job postings in the last six months.
How modern is the Leon tech stack?
Leon scores 66 out of 100 (Modern). The score averages how current each technology in the stack is and adds weight for AI adoption. AI technologies in the stack: 0; legacy ones: 0.
How does Alion know the Leon tech stack?
Alion reads every job posting Leon publishes and tags the technologies each one names. The figures on this page count the 27 postings of the last 12 months and were updated on Nov 14, 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, "Leon tech stack: 71 technologies from 27 job postings", as of Nov 14, 2026. https://alion.io/company/leon/technologies