Animation Digital Network (ADN) is one of Europe’s largest anime streaming platforms, with around 400,000 subscribers and 58% watching on mobile devices. ADN began as a French-language anime streaming service, expanded into Germany in 2023 and Poland in spring 2026, and has a fourth country launching soon (with several more planned for the future).
“We’re in the middle of ADN’s international expansion. That’s why monitoring with Sentry is becoming more and more important in our structure.”
William Yim, CTO
ADN CTO William Yim runs an engineering org of 22 developers split into multiple teams using Sentry: web, apps (mobile, TV, and gaming consoles), backend, back office for developing internal tools, and payments.
For a streaming service, a slow-loading screen can be the difference between a subscriber watching an episode or unsubscribing. And since the service is available via a browser app, iOS, Android, smart TVs, gaming consoles, and a growing list of countries, the surface area gets large quickly.
Actioning on User Feedback
“Before, from the moment we had the error to the moment we solved it, it was two to three hours, sometimes four. Now, when the error comes in on Sentry, we can fix it in 15 minutes to an hour.”
William Yim, CTO
ADN uses Sentry’s User Feedback widget to collect input from users. The QA team can field this feedback to work out what happened using the connected session replay, traces, and breadcrumbs before passing to the team responsible for a fix.
“The QA and developers quickly get an understanding of where the bug comes from, and they can use that to discuss how to fix it. The developers gain time, because it’s already filtered and the context is already there.”
William Yim, CTO
High severity bugs, prioritized via custom alerts, get routed straight to the developer responsible for the code. Everything is focused on preserving a high quality user experience across the platforms that ADN delivers content on:
“Every crash we see is a critical priority on our side. But sometimes you have issues that aren’t crashes and are still important, because they impact the user experience. We base our priority on the user experience.”
William Yim, CTO
Getting visibility across platforms and geos with dashboards
Each team builds and owns its own Sentry dashboards, covering iOS, Android, web, and internal tools. Inside each one, the team can filter by app version, region, platform, and environment (production, staging, or pre-production). The team monitors metrics like TTID (Time to Initial Display), cold/warm app starts, and frozen frame delays to ensure a strong user experience:
“We need to know how long the screen takes to display. Users complain that the application is slow to show some screens, so this information is pretty important for us.”
William Yim, CTO
Fixing app performance before users drop off
Sentry also helps ADN find where they can improve performance across their apps. Recently, they uncovered that they had a geolocation request that was taking around five seconds to respond:
“With the trace waterfall you can see how long each request is taking. We were able to see that this request was responding slowly, so we took action with the backend team to improve the response time.”
William Yim, CTO
After the fix, response time dropped to the millisecond range:
“Without Sentry it would have taken us a lot of time to pinpoint exactly what was happening and to understand and improve it.”
William Yim, CTO
The same workflow applies to screens as well as requests: the team uses Sentry profiling to understand which part of a screen is loading slowly and optimize that specific piece.
Watching every release
Sentry is a critical tool for ADN on release day. Release Health and crash-free rate are the first thing they check on any new version:
“Sentry is really the core application when we need to monitor the release health and the crash-free rate of every new version. We keep a constant eye on it when we release a new feature or a new version of the application or the website.”
William Yim, CTO
Because every dashboard carries an environment filter, the team watches a build through staging and pre-production before it reaches subscribers, and the version filter separates what’s breaking in the new release from what was already there. High-severity issues in a fresh release go to Slack and to the developer who owns the code.
The same data tells the team whether the feature they just shipped is landing.
“We use it to track bugs, but it also tells us how a feature is adopted and how users use it.”
William Yim, CTO
Why Sentry Works For Them
- Visibility across every platform → ADN can view performance and error data across iOS, Android, browser, TV, and consoles in one place, filtered by version, region, and environment instead of split across tools.
- Team coordination on fixes → Sentry helps the engineering team quickly understand where issues originate and which team is responsible for the fix.
- Faster resolution → Production issues resolved in 15 minutes to an hour, down from two to four hours.
- Quick action on user feedback → The team can see the attached replay, trace, and microservice already identified, so engineering time goes to the fix rather than figuring out what happened.
- Uncovering performance wins → Finding and fixing slow operations like a geolocation request responding in roughly five seconds, cut to milliseconds after it surfaced in the trace waterfall.
- Confidence on every release → Crash-free rate and feature adoption checked on each new version across four countries.
“The whole ecosystem is well done. It helps a lot, in a lot of cases, and everything is linked together.”
William Yim, CTO