Using the Irish experience of public investment and fiscal policy management over the last 25 years, we identify five core lessons. These concern (1) the need for sustained investment effort even when facing tough choices regarding public expenditure, (2) the importance of assessing the adequacy of public capital, (3) counter-cyclicality as an important principle of public investment, (4) crowding-in private investment and (5) the challenge for public investment caused by longer-term challenges such as the necessary climate transition. We also propose two overarching design suggestions for fiscal policy and investment management frameworks.