Achieving carbon neutrality by 2050 has become a central objective in national and regional climate strategies, yet the realization of this goal requires more than just high-level commitments—it demands a clear understanding of how various technologies contribute to emission reductions across time. Traditional scenario analyses often focus on optimizing macroeconomic costs and long-term energy mixes, while paying insufficient attention to the temporal evolution and system-level interactions of mitigation technologies. To address this gap, this chapter introduces an improved version of the Glocal Century Energy Environment Planning (G-CEEP) model, which embeds detailed energy technology modules into a comprehensive integrated assessment framework. This enhanced model enables more granular evaluation of technological contributions, cost implications, and policy priorities across different phases of the decarbonization transition. Model simulations show that while carbon neutrality is technically achievable, it requires a phased and adaptive strategy—beginning with low-cost interventions such as building efficiency improvements and on-site renewables, followed by the introduction of utility-scale imported solar and wind power during the mid-transition phase (2022–2028), and ultimately relying on flexible dispatchable technologies such as hydrogen, biomass, and fossil fuels with carbon capture and storage (CCS) in the later stages. Of particular importance is the finding that the optimal role of any given technology is highly dependent on the status and availability of others, making the decarbonization process a dynamic competition among technologies with varying costs and system flexibility. Furthermore, the study underscores the need to move beyond simplistic deployment targets for renewables and instead focus on the challenges of consumption, storage, and grid coordination. In doing so, the improved G-CEEP model offers a more realistic and policy-relevant tool for planning net-zero energy systems and provides critical insights into the sequencing, integration, and systemic balance of mitigation strategies across the full transition timeline.