Companies using Fastmail and Sentry

5 companies in our data have public evidence for both Fastmail and Sentry, and 5 name both in their own subprocessor list. Each company below links to the source for every claim. Our coverage is partial, so this is not everyone.

5companies use both

33%of Fastmail users

under 1%of Sentry users

5name both as subprocessors

Companies using one are 3.5 times as likely as the average company in our data to show evidence of the other.

The companies

Strongest evidence first: a company naming both in its own subprocessor list comes before one seen on its website or in job postings.

Subprocessor listPrivacy policyWebsiteJob postings

Company	Fastmail	Sentry
RenderFormrenderform.ioRenderForm is a graphics editor for designing templates that automate repetitive image, PDF, or video creation.Design and creative Developer tools
Sendmarcsendmarc.comSendmarc provides a platform for managing DMARC, SPF, and DKIM email authentication across domains.Cybersecurity
SimpleLocalizesimplelocalize.ioSimpleLocalize provides a web-based translation editor and platform for managing translations and automating localization workflows for software projects.Developer tools
Stadia Mapsstadiamaps.comStadia Maps provides map, geocoding, and routing APIs for developers.Developer tools
Fathom Analyticsusefathom.comFathom provides website analytics software that shows where visitors come from, which pages they read, and what converts without using cookies.Data and analytics

The two technologies

Fastmail

Email and communications

Fastmail is a paid email hosting service offering email, calendar, and contacts, with options for private email addresses and offline access. It is used by individuals and businesses to send, receive, organize, and manage email, calendars, and contacts across devices.

Summarized from fastmail.com on 8 Nov 2026.

33% of the 15 companies we see using Fastmail also show the other.

All 15 companies using Fastmail 12 name it as a subprocessor More in Email and communications

Sentry

by Functional Software · Observability

Sentry is an application monitoring and debugging platform that connects errors, logs, replays, traces, profiles, and metrics under the same trace. It is used by developers to find the root causes of application issues and fix them, from development through production.

Summarized from sentry.io on 8 Nov 2026.

under 1% of the 2,214 companies we see using Sentry also show the other.

All 2,214 companies using Sentry 1,634 name it as a subprocessor More in Observability

Other pairs

Companies with their own evidence for both.

More with Fastmail

Cloudflare15companies

Stripe9companies

Amazon Web Services6companies

Anthropic6companies

Hetzner6companies

Google5companies

More with Sentry

Cloudflare2,203companies

Google Workspace1,573companies

Amazon Web Services1,191companies

Stripe1,145companies

OpenAI924companies

Google891companies

Questions

How many companies use both Fastmail and Sentry?

5 companies in StrataDB's data have public evidence for both, and 5 of them name both in their own subprocessor list, the strongest evidence we hold. Our coverage is partial, so the real number is higher.

Which companies use Fastmail and Sentry?

RenderForm, Sendmarc, SimpleLocalize, Stadia Maps and Fathom Analytics. Each one links to the evidence behind it.

How does StrataDB know a company uses Fastmail and Sentry?

From four kinds of public evidence: subprocessor lists, privacy policies, website code and job postings. Each is kept apart with its source and the date we saw it. A company missing here means we found no evidence, not that it does not use them.

Find every company using Fastmail and Sentry

See the full list with the source for each company, and run the same lookup for any technology from the API, Claude or your browser.

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