Hi Maxi,
One possible approach for orientation: Take a look at which agencies are currently active in SEO or marketing competitions. These kinds of contests often give a good indication of who’s not just talking theory but actually delivering creative, hands-on solutions.
For example, in the ongoing SEO Contest 2025 based on the keyword "Keywordkönig", several agencies are publicly competing against each other.
One of the more eye-catching entries comes from Semtrix:
https://www.semtrix.de/keywordkoenig/
Whether that makes them the right partner for you is, of course, something you’d have to assess based on your specific needs. But contests like this can provide an initial impression of how agencies tackle complex topics, how creative they are, and how deep their expertise runs.
Especially if you're looking for more than just performance – things like concept, content, and strategic thinking – this can be a helpful filter.
Best regards