Even very small companies often keep their profits overseas because of a loophole in the way that trade law works. You can exploit loopholes pretty easily.

For example, say you own two companies (very cheap to set up legally, like a few thousand $ max), one the US-based Raven Computers LLC and the other the Latvian based Jackdaw INC. Jackdaw INC does two things: 1. it does all your business outside the USA, so it both sources, manufactures, assembles the computers, and sells them direct to customer. But in the USA, it doesn't do that last part. Instead, it serves as only the source for the computers, much the way that Falcon Northwest sources white-label asian computers for like 1/6 what they charge, then pimps them out state side to sell them for a massive mark up. So you buy the computers for $400 from Jackdaw and sell them for $800 as Raven.

You only report profit for tax purposes on the difference, so you just sold an 800 computer to yourself and avoided 50% of the taxes (the IRS will come after you if you do something really insane with the margins, like sell for $799.99 and resell for $800), but this all gets sticky with IP/Code/Web Development/etc. because it's much harder to pin a firm value on an intangable product that's unique and protected by patent laws. Unlike a bolt or a wrench, where the IRS can argue that no reasonable company would source a $18 wrench when the same one is available for $3, the SAAS application you're selling yourself might have strong enough IP protection that you can argue for a much less reasonable margin, and dodge, say, 90% of your tax obligation.

Taxes on foreign income are only incurred when the income is repatriated if the company is based in a country like Latvia or some South American companies with virtually no tax or a flat tax, so you can either defer taxes for decades, or if you're a true baller, you can just use those accounts when you travel overseas to fund vacations, tourism, etc. without it being taxed.