Carry Ivy is so flexible and universal in her strengths and itemization, that you almost never want to build the exact same items every game. For playing around the carry playstyle, core build is almost always the same, tesla is necessary for damage, and enduring speed is necessary for slide shooting consistently with max 2.0 items
Post-Core
Every single item can be insanely strong depending on the composition for both teams. Pay attention, and build whatever items are most necesasry per game. If your team has a lot of damage, but is lacking utility, consider more spirit items, and rushing vortex/lighting scroll earlier. If your team is lacking an M1 carry, consider buying more gun items for damage0 items