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Over the past decade, composite interacting light-matter systems have emerged as versatile platforms for exploring nonequilibrium phenomena in condensed matter physics. Owing to their driven-dissipative nature, these hybrid systems are subject to both atomic and photonic fluctuations, giving rise to rich dynamical behavior, including the emergence of metastable states. A metastable state is dynamically stable yet distinct from the thermodynamic ground state, and is therefore intrinsically nonequilibrium. This phenomenon is fundamentally different from prethermalization, where long-lived states arise due to approximate conservation laws rather than dynamical stabilization. In this talk, I will present two concrete examples, namely, an open photon Bose-Einstein condensate and nonequilibrium superradiant dynamics in dissipative Dicke model. In these systems, metastable states can emerge in both atomic and photonic degrees of freedom through different mechanisms of dynamical stabilization. References [1] M. Janning, R. Kramer, M. Turaev, S. Ray, and J. Kroha, Emergent thermal fluctuations and non-Hermitian phase transitions in open photon condensates, arXiv:2603.21927 (2026). [2] A. Abouelela, M. Turaev, R. Kramer, M. Janning, M. Kajan, S. Ray, and J. Kroha, Stabilizing Open Photon Condensates by Ghost-Attractor Dynamics, Phys. Rev. Lett. 135, 053402 (2025). [3] T. Wu, S. Ray, and J. Kroha, Temporal bistability in the dissipative DickeBose-Hubbard system, Ann. Phys. (Berlin) 536, 2300505 (2024). [4] S. Ray , A. Vardi, and D. Cohen, Quantum signatures in quench from chaos to superradiance, Phys. Rev. Lett. 128, 130604 (2022), |