# What does Callendar use?

Callendar (callendar.tech) shows public evidence of 10 tools, according to runsonwhat (last checked 2026-11-04).

- Industry: Software
- Based in: France
- Founded: 2019
- LinkedIn: https://www.linkedin.com/company/callendar

## Edge & Hosting

| Tool | Category | Evidence | Since |
|---|---|---|---|
| [Cloudflare](https://www.runsonwhat.com/reverse/cloudflare) | CDN & Edge | Website code |  |
| [Google Cloud](https://www.runsonwhat.com/reverse/gcp) | Hosting & Cloud | Website code |  |
| [OVHcloud](https://www.runsonwhat.com/reverse/ovh) | Hosting & Cloud | Custom domain, Email records, DNS records, Website code |  |

## Application

| Tool | Category | Evidence | Since |
|---|---|---|---|
| [GSAP](https://www.runsonwhat.com/reverse/gsap) | Media & UI | Website code |  |
| [React](https://www.runsonwhat.com/reverse/react) | Frontend | Website code |  |

## Data & Observability

| Tool | Category | Evidence | Since |
|---|---|---|---|
| [Sentry](https://www.runsonwhat.com/reverse/sentry) | Monitoring | Website code |  |

## Go-to-market

| Tool | Category | Evidence | Since |
|---|---|---|---|
| [Wix](https://www.runsonwhat.com/reverse/wix) | Website & CMS | Custom domain, Website code |  |

## Company Ops

| Tool | Category | Evidence | Since |
|---|---|---|---|
| [Microsoft 365](https://www.runsonwhat.com/reverse/microsoft-365) | Workspace | DNS verification records, Email records, Website code |  |

## Recent changes at Callendar

- 2026-11-04: started using [Cloudflare](https://www.runsonwhat.com/reverse/cloudflare)
- 2026-11-04: stopped using [Fastly](https://www.runsonwhat.com/reverse/fastly)

## FAQ

### What tools does Callendar use?

As of November 2026, runsonwhat has found 10 tools at Callendar (callendar.tech) in public records. Edge & Hosting: Cloudflare, Google Cloud and OVHcloud. Application: GSAP and React. Data & Observability: Sentry. Go-to-market: Wix. Company Ops: Microsoft 365. Last checked November 4, 2026.

### What cloud does Callendar run on?

Callendar uses Google Cloud for hosting and cloud infrastructure, alongside OVHcloud, according to runsonwhat (November 2026). runsonwhat found Google Cloud through Google Cloud code on callendar.tech. Google Cloud is used by 77,581 companies runsonwhat tracks.

### What email provider does Callendar use?

Callendar uses Microsoft 365 for email and office software, according to runsonwhat (November 2026). runsonwhat found Microsoft 365 through a DNS verification record for Microsoft 365 and email records. Microsoft 365 is used by 730,663 companies runsonwhat tracks.

### What is Callendar's website built with?

Callendar uses Wix for its website, according to runsonwhat (November 2026). runsonwhat found Wix through a subdomain that points at Wix and code on callendar.tech. Wix is used by 52,338 companies runsonwhat tracks.

### What monitoring tools does Callendar use?

Callendar uses Sentry for monitoring, according to runsonwhat (November 2026). runsonwhat found Sentry through Sentry code on callendar.tech. Sentry is used by 80,042 companies runsonwhat tracks.

### Does Callendar use Cloudflare?

Yes. runsonwhat found Cloudflare at Callendar through Cloudflare code on callendar.tech. Cloudflare is a CDN & Edge tool used by 731,346 companies runsonwhat tracks.

### Has Callendar changed tools recently?

Yes. On runsonwhat's rechecks, Callendar started using Cloudflare (latest on November 4, 2026) and stopped using Fastly (latest on November 4, 2026). A change counts only between two checks of callendar.tech done the same way.

### How does runsonwhat know what Callendar uses?

runsonwhat reads public records only. Of the 10 tools at Callendar, 6 were found through code on callendar.tech, 2 through subdomains that point at the vendor, 1 through DNS records and 1 through website configuration files. A tool is listed only when a direct record backs it up; DNS is rechecked weekly and callendar.tech about monthly.


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Source: runsonwhat, https://www.runsonwhat.com/company/callendar.tech (updated November 2026). Counts are companies with direct public evidence of the tool (DNS records, certificates, website code, a real-browser crawl, subprocessor lists), so they are lower bounds. Methodology: https://www.runsonwhat.com/methodology.