If you come here after having read (parts of?) the thesis, then first of all my gratitude to you, the reader, for having spent time with my writing. It means a lot.

Of course, without Klaus Desch I wouldn't even have been able to work on this thesis. Thanks a lot, Klaus. And especially thank you for taking the time to do our personal meetings these last years. I really appreciate it!

Next, I want to thank everyone in our group. Although, especially since COVID hit I haven't been to the office much, it was always a great environment to work in. Most notably I want to thank Tobias (Schiffer) and Markus (Gruber) as my longest office mates. We had a lot of fun together (maybe some days a bit too much, hehe) and I hope we can continue even when I'm not around anymore! Johanna (von Oy), you came later, but that doesn't mean I didn't enjoy working with you. On the contrary, it was great. Thanks to being open minded about my software ideas. :)

Some people in our group left a while ago, but you're not forgotten. Christoph (Krieger), thank you for your supervision all those years ago. I hope you are satisfied with my work and maybe a little bit proud! Lucian (Scharenberg), you technically didn't really 'leave' until recently, but we didn't see each other much with you being at CERN for your PhD. Also thank you for the good times and we'll keep in touch! Hendrik (Schmick), although you were only around for the year of your master thesis, it was a lot of fun to supervise you! The same holds for Jannes (Schmitz), even though it was even shorter with his Bachelor thesis.

During my years of the thesis I spent a significant chunk of time at CERN. I want to extend my gratitude to everyone in the CAST collaboration. You're a great bunch of people! Thank you for being welcoming and supportive. Konstantin (Zioutas), Giovanni (Cantatore), Horst (Fischer), your focus was elsewhere in those last years of CAST of course, but I appreciated your feedback and it was fun working with you! Theodoros (Vafeiadis), a special thanks goes to you for not only being an excellent technical coordinator, but also just being fun and helpful outside of work! Marios (Maroudas) and Justin (Baier) thank you two as well. And Cristian (Cogollos) and Sergio (Arguedas) I loved our time together sharing "the corridor". You know who you are!

While I am not part of the group of Igor (García Irastorza) in Zaragoza, I spent a lot of time in the last few years in Zaragoza. Everyone of you treated me as if I was part of your group (aside from being IAXO collaboration members!). Thank you all! Special thanks go out to Julia (Vogel) and Jaime (Ruz) for their efforts in helping me understand the LLNL telescope! And Konrad (Altenmüller), thanks for 'abseiling' into my life via your postdoc, haha! And Igor, thank you for helping me untangle the limit calculation.

On a completely different side of things, thanks to Andreas (Rumpf, @araq) for inventing the Nim programming language. Without you my thesis would certainly be different! Generally, the Nim community is a great bunch of really talented people (give Nim a try!). Too many to list here, but I want to highlight a few. Mamy (Ratsimbazafy, @mratsim) your work is extremely appreciated, not only by me as you very well know. And I'm especially grateful to you, for being as trusty as you were right from the start. You didn't know me, but you treated me with respect and collaborated with me, which gave me a huge boost in confidence to put my own code out there! Brent (Pedersen, @brentp), thanks for developing nim-plotly. It was really helpful in getting started to use Nim for my work! The same goes for Yuriy (Glukhov @yglukhov), being able to interact seamlessly with Python from Nim via nimpy was exceptionally useful. Regis (Caillaud, @clonkk) and Hugo (Granström @hugogranstrom), I love collaborating with you guys. Thanks for working with me on SciNim. Onto the future! And finally, Chuck (Charles Blake @c-blake), thank you for being a mentor and friend. :)

I consider most of the people I named above good friends, but mention you in a context that somehow relates to the thesis. A few people should be mentioned though that don't really fit in like that!

First, David (Helten), I hope we manage to stay in contact better again in the future! Stephan (Kürten), a big thank you to you, too (and of course for proofreading!). And Roberto (Röll), thanks for always being there for me (and reading the thesis!).

And finally, thanks to my family. Danke, Bianca, Papa und Mama, dass es euch gibt! And thank you Cristina (Margalejo) for being my partner and being at my side!