What does an optimizer do?

In plain terms: an optimizer searches for the best plan under rules you care about, instead of following a single rule of thumb. For retirement and tax-aware planning, that usually means looking across years and across accounts (taxable, tax-deferred, and Roth-style) and proposing where holdings should sit, where new savings should go, and where money should come from when you spend. It has to respect real limits at the same time: contribution caps, account eligibility, tax treatment, your chosen goal (paycheck, wealth, taxes, or legacy), and the mix of investments you already want to keep. Think of it as putting those constraints on a scale and finding a balance that fits the whole picture: not optimizing one shelf while ignoring the rest. The output is a optimized plan of moves over time under those assumptions; it is still a recommendation to discuss with a professional, not a guarantee.