# What does Yellow use? Yellow (yellow.systems) shows public evidence of 26 tools, according to runsonwhat (last checked 2026-11-10). - Industry: Software - Size: 51–200 employees - Based in: San Francisco, United States - Founded: 2015 - LinkedIn: https://www.linkedin.com/company/yellow-systems ## 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 | Custom domain | | | [Heroku](https://www.runsonwhat.com/reverse/heroku) | Hosting & Cloud | Custom domain, Website code | | | [DNSimple](https://www.runsonwhat.com/reverse/dnsimple) | DNS | DNS records | | ## Application | Tool | Category | Evidence | Since | |---|---|---|---| | [React](https://www.runsonwhat.com/reverse/react) | Frontend | Website code | | | [Next.js](https://www.runsonwhat.com/reverse/nextjs) | Frontend | Website code | | | [Three.js](https://www.runsonwhat.com/reverse/threejs) | Media & UI | Website code | | ## Data & Observability | Tool | Category | Evidence | Since | |---|---|---|---| | [Google Analytics](https://www.runsonwhat.com/reverse/ga) | Analytics | Website code | | | [Google Tag Manager](https://www.runsonwhat.com/reverse/gtm) | Analytics | Website code | | | [Sentry](https://www.runsonwhat.com/reverse/sentry) | Monitoring | Website code | | | [Hotjar](https://www.runsonwhat.com/reverse/hotjar) | Analytics | Website code | | ## Go-to-market | Tool | Category | Evidence | Since | |---|---|---|---| | [Google Ads](https://www.runsonwhat.com/reverse/google-ads) | Ads & Pixels | Website code | | | [Meta Pixel](https://www.runsonwhat.com/reverse/meta-pixel) | Ads & Pixels | Website code | | | [WhatsApp Business](https://www.runsonwhat.com/reverse/whatsapp) | Support & Docs | Website code | | | [LinkedIn Insight Tag](https://www.runsonwhat.com/reverse/linkedin-insight) | Ads & Pixels | Website code | | | [Mailchimp](https://www.runsonwhat.com/reverse/mailchimp) | Marketing | Website code | | | [Calendly](https://www.runsonwhat.com/reverse/calendly) | Sales & CRM | Website code | | | [ChatGPT Ads](https://www.runsonwhat.com/reverse/chatgpt-ads) | Ads & Pixels | Website code | | | [Yandex Webmaster](https://www.runsonwhat.com/reverse/yandex) | Marketing | DNS verification records | | | [Dealfront](https://www.runsonwhat.com/reverse/leadfeeder) | Sales & CRM | Website code | | | [Contentful](https://www.runsonwhat.com/reverse/contentful) | Website & CMS | Website code | | | [Snitcher](https://www.runsonwhat.com/reverse/snitcher) | Sales & CRM | 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 | | | [Mailchimp Transactional](https://www.runsonwhat.com/reverse/mandrill) | Email Delivery | Email records | | ## Recent changes at Yellow - 2026-11-10: stopped using [llms.txt](https://www.runsonwhat.com/reverse/llms-txt) ## FAQ ### What tools does Yellow use? As of November 2026, runsonwhat has found 26 tools at Yellow (yellow.systems) in public records. Edge & Hosting: Cloudflare, Google Cloud and Heroku. Application: React, Next.js and Three.js. Data & Observability: Google Analytics, Google Tag Manager and Sentry. Go-to-market: Google Ads, Meta Pixel and WhatsApp Business. Company Ops: Microsoft 365, Google Workspace and Mailchimp Transactional. Last checked November 10, 2026. ### What cloud does Yellow run on? Yellow uses Google Cloud for hosting and cloud infrastructure, alongside Heroku, according to runsonwhat (November 2026). runsonwhat found Google Cloud through a subdomain that points at Google Cloud. Google Cloud is used by 77,682 companies runsonwhat tracks. ### What sales tools does Yellow use? The sales tools runsonwhat has found at Yellow are Calendly, Dealfront and Snitcher (November 2026); no CRM shows up in Yellow's public records. runsonwhat found Calendly through Calendly code on yellow.systems. ### What email provider does Yellow use? Yellow uses Microsoft 365 for email and office software, alongside Google Workspace, according to runsonwhat (November 2026). runsonwhat found Microsoft 365 through a DNS verification record for Microsoft 365. Microsoft 365 is used by 732,144 companies runsonwhat tracks. ### What does Yellow use for customer support? Yellow uses WhatsApp Business for customer support and documentation, according to runsonwhat (November 2026). runsonwhat found WhatsApp Business through WhatsApp Business code on yellow.systems. WhatsApp Business is used by 138,741 companies runsonwhat tracks. ### What analytics tools does Yellow use? Yellow uses Google Analytics for analytics, alongside Google Tag Manager and Hotjar, according to runsonwhat (November 2026). runsonwhat found Google Analytics through Google Analytics code on yellow.systems. Google Analytics is used by 903,831 companies runsonwhat tracks. ### Does Yellow use Cloudflare? Yes. runsonwhat found Cloudflare at Yellow through Cloudflare code on yellow.systems. Cloudflare is a CDN & Edge tool used by 732,181 companies runsonwhat tracks. ### Has Yellow changed tools recently? Yes. On runsonwhat's rechecks, Yellow stopped using llms.txt (latest on November 10, 2026). A change counts only between two checks of yellow.systems done the same way. ### Which companies have a tech stack similar to Yellow's? The companies with the stacks most like Yellow's are Cyzag, Sentry Interactive, Cerrix and Bluedot, according to runsonwhat (November 2026). Each shares 6 to 10 tools with Yellow, and rare tools count for more than common ones like Google Workspace, so the match reflects real stack choices. ### How does runsonwhat know what Yellow uses? runsonwhat reads public records only. Of the 26 tools at Yellow, 18 were found through code on yellow.systems, 4 through DNS records, 2 through email records and 2 through subdomains that point at the vendor. A tool is listed only when a direct record backs it up; DNS is rechecked weekly and yellow.systems about monthly. --- Source: runsonwhat, https://www.runsonwhat.com/company/yellow.systems (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.