On the same €65,000 gross, a worker takes home roughly €11,716 more per year in Ireland than in Germany. That gap reflects the tax structure alone — before rent, healthcare, or savings behaviour come into play.
Housing is the first multiplier. Ireland has very high rent pressure, while Germany has moderate rent pressure. That means part of the higher take-home in Ireland can be absorbed by rent if you land in a major city.
Healthcare and pensions go in the opposite direction. Ireland runs a mixed healthcare model — Mixed: HSE public system plus widespread private cover for faster access. Germany uses a public model — Statutory health insurance (~14.6% split with employer) gives full coverage. The country with lower take-home often shifts costs that the other country leaves to your private budget.
Net-of-everything, a relocation decision should weigh strong public welfare in Ireland against comprehensive welfare state in Germany, plus differences in pension capture, social safety nets, and city-level cost of living.