Tellis Katsogiannos started his fly fishing journey in the mid 90´s with trout being his favorite species for many years. He later on started swinging flies for trout and salmon around 2002 and fell in love with the whole concept of "Spey fishing". Even though Atlantic salmon has been his favorite for many years, the last decade he just loves swinging flies regardless of species. Fly casting has always been a huge part of his life. Even before he understood anything about the mechanics of it, he understood that we are the ones forming that loop and it is always telling us something.

In 2006, he started his own business "Tellis Fly Fishing" where he provided guiding, fly casting lessons, and hosted trips, as well as having an online shop with mainly fly tying materials as a start. In 2012, he launched his own brand of fly rods and fly lines which became very popular, especially in Scandinavia.

His interest in fly casting also took another big leap in 2010 as he entered the first official ICSF World championship in fly casting and has been competing ever since. In 2016, he became World champion in 15´1 Spey distance and has 2 silver and 2 bronze medals from other years. Being friends with many wonderful people from Fly Fishers International, led him to later on become a certified instructor within FFI (CI and THMCI) in 2017.

Up until 2022 he kept working and growing his business, but that same year Guideline Flyfish came with an offer that was too good to resist and so he gradually took over product development from Leif Stävmo. Over the last 2 years Tellis worked as Guidelines new product developer on fly rods and fly lines.