This paper explores the mechanism of dark matter (DM) freeze-in at stronger coupling in the early universe. The key idea is that DM is produced through interactions with the Standard Model (SM) thermal bath, but with a much stronger coupling than in traditional freeze-in models. This allows for a lower reheating temperature, which suppresses DM production via Boltzmann suppression. The SM sector temperature remains constant or decreases slowly before reheating, enabling DM to be produced efficiently at the maximum temperature of the SM bath. The study considers a scenario where the inflaton decays into feebly interacting right-handed neutrinos (ν_R), which then decay into SM particles. This process leads to a constant SM temperature before reheating, making the maximal and reheating temperatures close. The DM abundance is calculated using the Boltzmann equation, showing that the DM production is most efficient when the SM temperature is at its maximum. The paper demonstrates that the freeze-in mechanism can be realized in a UV complete framework, where the SM sector temperature remains constant or decreases slowly. This allows for a reliable calculation of DM abundance without the initial conditions problem of high reheating temperature models. The results show that the coupling between DM and the SM sector can be significant, making DM potentially observable in direct detection experiments and at the LHC. The study also addresses the issue of gravitational dark matter overproduction, which is avoided in this scenario due to the low reheating temperature. The DM abundance is sensitive to the thermal history of the SM sector, particularly the relation between the maximal and reheating temperatures. The results show that the coupling vs mass relation is close to that computed in the instant reheating approximation when T_R ≈ T_max. If the maximal and reheating temperatures differ, the coupling receives a rescaling factor. The paper concludes that freeze-in at stronger coupling is a well-motivated scenario that addresses the initial conditions problem in conventional freeze-in models. It allows for a low reheating temperature, making DM production Boltzmann-suppressed and potentially observable in direct detection experiments. The results also show that the DM abundance is sensitive to the thermal history of the SM sector, and the coupling vs mass relation is close to that computed in the instant reheating approximation when T_R ≈ T_max. The study highlights the importance of understanding the thermal evolution of the SM sector in the early universe for accurately predicting DM abundance.This paper explores the mechanism of dark matter (DM) freeze-in at stronger coupling in the early universe. The key idea is that DM is produced through interactions with the Standard Model (SM) thermal bath, but with a much stronger coupling than in traditional freeze-in models. This allows for a lower reheating temperature, which suppresses DM production via Boltzmann suppression. The SM sector temperature remains constant or decreases slowly before reheating, enabling DM to be produced efficiently at the maximum temperature of the SM bath. The study considers a scenario where the inflaton decays into feebly interacting right-handed neutrinos (ν_R), which then decay into SM particles. This process leads to a constant SM temperature before reheating, making the maximal and reheating temperatures close. The DM abundance is calculated using the Boltzmann equation, showing that the DM production is most efficient when the SM temperature is at its maximum. The paper demonstrates that the freeze-in mechanism can be realized in a UV complete framework, where the SM sector temperature remains constant or decreases slowly. This allows for a reliable calculation of DM abundance without the initial conditions problem of high reheating temperature models. The results show that the coupling between DM and the SM sector can be significant, making DM potentially observable in direct detection experiments and at the LHC. The study also addresses the issue of gravitational dark matter overproduction, which is avoided in this scenario due to the low reheating temperature. The DM abundance is sensitive to the thermal history of the SM sector, particularly the relation between the maximal and reheating temperatures. The results show that the coupling vs mass relation is close to that computed in the instant reheating approximation when T_R ≈ T_max. If the maximal and reheating temperatures differ, the coupling receives a rescaling factor. The paper concludes that freeze-in at stronger coupling is a well-motivated scenario that addresses the initial conditions problem in conventional freeze-in models. It allows for a low reheating temperature, making DM production Boltzmann-suppressed and potentially observable in direct detection experiments. The results also show that the DM abundance is sensitive to the thermal history of the SM sector, and the coupling vs mass relation is close to that computed in the instant reheating approximation when T_R ≈ T_max. The study highlights the importance of understanding the thermal evolution of the SM sector in the early universe for accurately predicting DM abundance.