The verdict
For a small B2B team, pick Toptal when a wrong hire would be expensive and you need a senior person soon, such as a lead developer or a fractional finance lead. You pay for the screening and skip the sorting.
Pick Upwork when the scope is defined and bounded, you have time to write a clear brief, and you want to compare many offers. A landing page, a data clean-up or a short bookkeeping project are typical.
If budget is tight, Upwork gives you more room to compare. If speed and certainty matter more, Toptal does. Do not use either for a permanent teammate.