Early hiring is not about filling a seat. Your first few engineers set the technical bar, the working norms, and the reputation that determines who you can recruit next. Get the first one right and the next ten get easier. Get it wrong and you spend a year unwinding it.
The trap most founders fall into is optimizing for raw speed — hiring the first competent person who says yes. At seed stage you cannot afford a 'competent' hire. You need someone who can own an ambiguous problem end to end, make architectural calls that won't need to be redone in six months, and raise the bar for everyone who follows.
Before you write a job description, get specific about the one or two things this hire must be exceptional at, and what you are willing to trade away. A founding engineer who is brilliant at zero-to-one but mediocre at process is usually the right call early; the reverse rarely is.
Finally, treat the first hire as a recruiting multiplier, not just an IC. The strongest builders want to work with other strong builders. Your first great hire is the proof point that lets you land the next five.