Jannusch logged 11 years as a head coach at both Ashford University (Iowa) from 2010-16 and the University of Incarnate Word (Texas), from 2002-07. His overall head coaching record is 290-282. Ashford closed its campus doors after the 2016 season, but not before the Saints claimed its first conference title in program history. The National Tournament appearance was also Ashford’s first-ever.

Ashford won a record 30 games in their final season, and Jannusch coached four NFCA all-region student-athletes. In all, Jannusch had eight all-region selections in just six seasons. Ashford softball student-athletes were recognized 33 times on the all-conference list, in both the Midwest Collegiate Conference and the Association of Independent Institutions.

In May of 2016, three Saints were inducted into the Ashford University Athletics Hall of Fame: Outfielder Alex Bitto, catcher Shelby Hobelman and pitcher Nicole Schmidt, all playing their entire careers under Jannusch. He is the all-time winningest coach in AU softball history. Jannusch is also a member of the Ashford Athletics Hall of Fame.

During his time at Incarnate Word, Jannusch's teams flourished. The best season came in 2007, when the Cardinals finished with a school-record 46 wins, and a runner-up finish in the NCAA Division II South Central Regional Tournament. Re-writing the single-season record book, the Cardinals earned the first-ever D2 ranking for the program, peaking at No. 14 in the 2007 postseason poll. Jannusch is second all-time in wins at UIW.

Other stops include Texas State (1996), St. Edwards (1997-2000), Evansville (2007), Lincoln (2009), Texas-San Antonio (2017) and Kansas Wesleyan (2018). Jannusch also founded and coached the Hearts of Texas Girls Fastpitch Club, from 1997-2007.

A long-time member of the National Fastpitch Coaches Association, Jannusch obtained a bachelor's degree in sports management from Colorado-Mesa, in Grand Junction.