Agenda 2030 and sustainable development goals (SDG) are key formulations of sustainability policies, consisting of 17 general-level goals and 169 more detailed targets. The target setting is based on tedious international policy negotiations and compromises addressing myriad of different and sometimes incompatible interests. Identification of key trade-offs and synergies between the targets can help the efficient implementation of SDGs by improving the opportunities to focus policy attention and actions on the most relevant issues. This article focuses on trade-offs and synergies of nationally relevant targets in the context of an industrialised and affluent nation state. Results from a cross-matrix examination of targets in Finland show that most of the selected targets are characterised by synergistic interactions with other nationally relevant targets. However, policies aimed at advancing economic growth and the use of renewable energy risk a number of serious trade-offs. Methodological advances are required to make the assessment of interactions more transparent and reliable, manageable within the limited resources and capable of producing results relevant to decision-making. A recommendation for the use of cross-matrix examination as a tool of collaborative ex ante sustainability assessment is put forward, also acknowledging the risk of "paralysis by analysis" related to the wide-ranging SDG framework.