# What does Closure use?

Closure (closure.nl) shows public evidence of 17 tools, according to runsonwhat (last checked 2026-10-23).

- Industry: IT Services
- Size: 11–50 employees
- Based in: Rotterdam, Netherlands
- Founded: 2018
- LinkedIn: https://www.linkedin.com/company/closure_services

## Edge & Hosting

| Tool | Category | Evidence | Since |
|---|---|---|---|
| [Amazon Web Services](https://www.runsonwhat.com/reverse/aws) | Hosting & Cloud | Website code |  |
| [Amazon Route 53](https://www.runsonwhat.com/reverse/route53) | DNS | DNS records |  |
| [Google Cloud](https://www.runsonwhat.com/reverse/gcp) | Hosting & Cloud | Custom domain |  |
| [Amazon CloudFront](https://www.runsonwhat.com/reverse/cloudfront) | CDN & Edge | Custom domain, Website code |  |

## Application

| Tool | Category | Evidence | Since |
|---|---|---|---|
| [React](https://www.runsonwhat.com/reverse/react) | Frontend | Website code |  |
| [Tailwind CSS](https://www.runsonwhat.com/reverse/tailwind) | Frontend | Website code |  |
| [Gatsby](https://www.runsonwhat.com/reverse/gatsby) | Frontend | Website code |  |

## Data & Observability

| Tool | Category | Evidence | Since |
|---|---|---|---|
| [Oh Dear](https://www.runsonwhat.com/reverse/ohdear) | Monitoring | Custom domain |  |

## Go-to-market

| Tool | Category | Evidence | Since |
|---|---|---|---|
| [Leadinfo](https://www.runsonwhat.com/reverse/leadinfo) | Sales & CRM | Website code |  |
| [Ortto](https://www.runsonwhat.com/reverse/ortto) | Marketing | Email records |  |
| [Trengo](https://www.runsonwhat.com/reverse/trengo) | Support & Docs | Website code |  |

## Company Ops

| Tool | Category | Evidence | Since |
|---|---|---|---|
| [Microsoft 365](https://www.runsonwhat.com/reverse/microsoft-365) | Workspace | DNS verification records |  |
| [Google Workspace](https://www.runsonwhat.com/reverse/google-workspace) | Workspace | Email records, Website code |  |
| [Atlassian](https://www.runsonwhat.com/reverse/atlassian) | Dev Tools | DNS verification records |  |
| [Mailgun](https://www.runsonwhat.com/reverse/mailgun) | Email Delivery | Email records, Website code |  |
| [Detectify](https://www.runsonwhat.com/reverse/detectify) | Security & Compliance | DNS verification records, Website code |  |

## FAQ

### What tools does Closure use?

As of October 2026, runsonwhat has found 17 tools at Closure (closure.nl) in public records. Edge & Hosting: Amazon Web Services, Amazon Route 53 and Google Cloud. Application: React, Tailwind CSS and Gatsby. Data & Observability: Oh Dear. Go-to-market: Leadinfo, Ortto and Trengo. Company Ops: Microsoft 365, Google Workspace and Atlassian. Last checked October 23, 2026.

### What cloud does Closure run on?

Closure uses Amazon Web Services for hosting and cloud infrastructure, alongside Google Cloud, according to runsonwhat (October 2026). runsonwhat found Amazon Web Services through Amazon Web Services code on closure.nl. Amazon Web Services is used by 145,983 companies runsonwhat tracks.

### What sales tools does Closure use?

The sales tools runsonwhat has found at Closure are Leadinfo (October 2026); no CRM shows up in Closure's public records. runsonwhat found Leadinfo through Leadinfo code on closure.nl. Leadinfo is used by 5,985 companies runsonwhat tracks.

### What email provider does Closure use?

Closure uses Microsoft 365 for email and office software, alongside Google Workspace, according to runsonwhat (October 2026). runsonwhat found Microsoft 365 through a DNS verification record for Microsoft 365. Microsoft 365 is used by 715,050 companies runsonwhat tracks.

### What does Closure use for customer support?

Closure uses Trengo for customer support and documentation, according to runsonwhat (October 2026). runsonwhat found Trengo through Trengo code on closure.nl. Trengo is used by 310 companies runsonwhat tracks.

### What marketing software does Closure use?

Closure uses Ortto for marketing, according to runsonwhat (October 2026). runsonwhat found Ortto through email records that authorize Ortto. Ortto is used by 682 companies runsonwhat tracks.

### Does Closure use React?

Yes. runsonwhat found React at Closure through React code on closure.nl. React is a Frontend tool used by 124,148 companies runsonwhat tracks.

### Which companies have a tech stack similar to Closure's?

The companies with the stacks most like Closure's are Youbahn, Twixl, Stackable and Fathom Analytics, according to runsonwhat (October 2026). Each shares 4 to 6 tools with Closure, and rare tools count for more than common ones like Google Workspace, so the match reflects real stack choices.

### How does runsonwhat know what Closure uses?

runsonwhat reads public records only. Of the 17 tools at Closure, 6 were found through code on closure.nl, 5 through DNS records, 3 through email records and 3 through subdomains that point at the vendor. A tool is listed only when a direct record backs it up; DNS is rechecked weekly and closure.nl about monthly.


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Source: runsonwhat, https://www.runsonwhat.com/company/closure.nl (updated October 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.