Johnsen Del Rosario tau koom nrog The kNOw Youth Media ua tus tshaj xov xwm hluas hauv 2015, sau ntawv txog kev noj qab haus huv thiab kev ncaj ncees hauv zej zog. Raws li tus kws sau xov xwm, nws tau sau cov duab tshiab, "Peb Tau Txais Li Cas? Fresno,” saib qhov tob ntawm Fresno txoj kev nom kev tswv, kev sib raug zoo, haiv neeg, thiab keeb kwm nyiaj txiag zoo li cas lub nroog Fresno mus rau niaj hnub no. Hauv xyoo 2018, nws tau koom nrog yli ua tus pabcuam pabcuam rau The kNOw Youth Media.
Tam sim no ua tus Thawj Saib Xyuas Haujlwm Loj, Johnsen txhawb nqa cov neeg ua haujlwm hauv kev tshaj xov xwm, hais dab neeg, thiab kev ua yeeb yam hauv Fresno County, thiab kev tawm tswv yim thiab kev koom tes rau pej xeem hauv Madera County. Pab 50+ cov tub ntxhais hluas ib xyoos ib zaug, cov kev pab cuam thiab cov phiaj xwm no tsom mus rau kev txhim kho kev coj noj coj ua, kev tawm tswv yim tawm tswv yim, thiab kev hloov kev piav qhia los ntawm kev hais dab neeg thiab kev sau xov xwm.
Johnsen kawm tiav qib siab hauv Mass Communications thiab Journalism los ntawm California State University, Fresno thiab yog ib feem ntawm Fusion's Rise Up: Be Heard journalism kev sib raug zoo hauv 2017 thiab Alliance for Boys & Men of Color data fellowship in 2024.