Young planets form a unique bridge between planet-forming protoplanetary disks and mature planets. In order to infer the internal and atmospheric structure of these young inflated planets, it becomes important to have high-precision measurements of their mass and radius. The V1298 Tau system, only a mere 23 Myrs old, is a keystone multi-planetary system hosting four transiting planets. Since the planets orbit a highly variable star, constraining the mass of the planets using radial velocities becomes a challenge. In such a scenario, using transit-timing variations (TTVs) provides another avenue to constrain the mass of the planets. In this poster, I will present high-precision transit observations of the first three planets in the V1298 Tau system using the CHEOPS telescope. I will provide an insight into the data analysis methodology used to encounter the unique systematics of CHEOPS. I will also briefly discuss the decorrelation methods used to tackle stellar variability evident in the observations. Finally, I will present the improvement in the transit parameters of the three young planets, place these observations in the context of HST and Spitzer observations of this system, and how these observations will help in constraining the mass of the planets using TTV models. Furthermore, I will discuss the implications of these measurements in terms of formation and early evolution of sub-Neptune planets.