Interviewing for startups : are formal cover letters + suits necessary, neutral, or harmful?

When one is applying to a startup of less than 20 people, is it necessary to use a formal cover letter, or will a simple, polite email do? I dislike cover letters because they feel extremely artificial. In my CL template, I end up talking about how, in high school, I woke up at 5:00 am to practice for contest math tests (e.g. USAMO). It makes me sound impressive and hard-working to HR people, but as I'm 25 and that was in HS, this sort of detail is completely irrelevant to whether or not I can write code.

Also, is it a good idea to wear a suit for a startup interview, or is this over-the-top or absurd? I'm afraid that overdressing might make it appear like I don't know how to interview for startups or, worse yet, type-cast me as similar to the species of douchebag college kid that generally applies for I-banking positions.

If it's not necessary to use cover letters and wear suits for startups, the next question is: where does one draw the line? How does one determine in advance whether or not an interview necessitates a suit?

These things depend on location. Where are you? Here's how things work in SV.

Cover letter is exceptionally useful. It should explain in simple English why you are qualified for this particular job, highlighting relevant experience and showing that you actually bothered to figure out what this job/company is about. Doing this well is a huge advantage. At your level 1 out of 100 applicants will do it right. Cover letter should be just natural part of the body of the email and be in plain text. It should not be formal.

Suit with no tie is appropriate if you are interviewing for a job of CEO. Suit with a tie is never appropriate. This is different on east coast.

I've always thought for most hackers that the only thing you'll need aside from a shirt and jeans is your brain.

B.Y.O.B.

:)

I've never interviewed in a suit, and I've been offered every job I've managed to get to the interview stage for. The most I've worn is formal shirt, slacks, nice shoes, and a tie, and that was once for a temp agency (and it was probably too much), another time for an event production company (it was DEFINITELY way too much), and a video game QA company (I could have worn less but it didn't seem to matter).

The event production company was pretty close to being a startup, and it was clear from the moment the door opened and I saw the place and the employees that I was overdressed.

I don't remember what I wore to interview for the video game company I worked for a few years ago, but I'm pretty sure it wasn't too fancy. If I was interviewing for a startup with less than twenty employees, I'd be pretty comfortable showing up in jeans and a collared shirt of some sort.

Agreed on taking out high school. I'm 28 and recently began taking out all references to college as well a couple years ago (my resume lists my degrees).

I agree dress like the job you want to have, but I disagree with the t-shirt bit. I've worked at 4 different companies, and always show up wearing professional, clean clothes to my interview (suit and tie the first time, since then just button down shirts and dress pants or khakis).

The t-shirt and jeans can wait until you've proven yourself for a few months. I go to work now in shorts and a t-shirt, so this isn't some sour grapes rant. Though I dress casual for work, given a choice between two identical, impeccably groomed, candidates one who came professionally dressed and one who came in shorts and a t-shirt (and that being the only difference), I would be likely to hire the one who came like he was here to interview.

Of course, I would hire someone casually dressed who knows their stuff over an idiot who happens to be wearing a suit, but I don't think there's any reason to put yourself at a disadvantage. Don't overdress, don't underdress - wear clothes appropriate for the interview.