ONCE tech stack
ONCE builds mostly with C#, JavaScript, Kotlin, Swift. Its stack also includes Windows, Flutter, MAUI. C# is named in 1 of the 6 job postings ONCE published in the last 12 months (17%). Counted by Alion from the job postings of ONCE, updated Oct 28, 2026.
What programming languages does ONCE use?
C# is named in 17% of job postings at ONCE, followed by JavaScript (17%), Kotlin (17%), Swift (17%).
What frameworks and libraries does ONCE use?
Flutter is named in 17% of job postings at ONCE, followed by MAUI (17%), React Native (17%), React.js (17%).
What cloud and platforms does ONCE use?
Windows is named in 17% of job postings at ONCE.
What developer tools does ONCE use?
Copilot is named in 83% of job postings at ONCE, followed by Git (17%), Rest API (17%).
How does your stack fit ONCE?
How modern is the ONCE stack?
ONCE scores 78 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: 0; legacy ones: 0.
How common is the ONCE stack in its industry?
Share of the 2,197 companies in the same industries, whose stack Alion knows, that use each technology.
Companies with a stack like ONCE
Questions about the ONCE tech stack
What programming languages does ONCE use?
The languages named in ONCE job postings are C# (17%), JavaScript (17%), Kotlin (17%), Swift (17%), Dart (17%), as a share of the 6 postings of the last 12 months.
What cloud and platforms does ONCE use?
The cloud and platforms named in ONCE job postings are Windows (1) (postings in brackets).
Is the ONCE tech stack changing?
No new technology has appeared in ONCE job postings in the last six months.
How modern is the ONCE tech stack?
ONCE scores 78 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: 0; legacy ones: 0.
How does Alion know the ONCE tech stack?
Alion reads every job posting ONCE publishes and tags the technologies each one names. The figures on this page count the 6 postings of the last 12 months and were updated on Oct 28, 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, "ONCE tech stack: 13 technologies from 6 job postings", as of Oct 28, 2026. https://alion.io/company/web-once/technologies