President’s Trump’s multibillion-dollar project to build a wall along the U.S.-Mexico border seems to be moving full steam ahead. Last Friday, the Department of Homeland Security began accepting proposals for two different barriers: a concrete wall and one made of an unspecified type of material -- presumably to be used in different areas of the border, depending on things like terrain.

There are more than 700 companies -- many based in California -- interested in some part of building the wall, which could cost more than $20 billion. All these companies have signed up on the Federal Business Opportunities website, where companies big and small go in search of federal contracts.

But there's more political blowback for the "big, beautiful wall" Trump has repeatedly promised to build. The project is so unpopular in California that some cities say they'll try to bar companies from city contracts if they help build the wall, and some Democratic lawmakers have introduced legislation to divest the state employee pension fund from any businesses that work on it.

You might think the companies interested in building a border wall would be mostly construction contractors, but there’s actually a wide range of vendors vying for the work.

Liz Derr is co-founder of Simularity, an East Bay artificial intelligence software company based in Richmond.

“We essentially look for patterns ... in massive amounts of data,” Derr says.

She says their software can analyze all kinds of data, like imagery from satellites and drones and vibrations from sensors, which she says could be useful along the border.

“It can tell the difference between a four-legged coyote and a two-legged coyote that is smuggling people," Derr says.

She says she actually doesn’t support building a border wall. But if it’s going to happen, she says, the government should be smart about it and build a virtual one.

“It’s our taxpayer dollars,” Derr says. “It’s ridiculous in my mind to go build this giant wall for billions of dollars when we can do something better for much less money.”

But there are plenty of companies interested in building a giant concrete wall.

“My wall design actually goes underneath the ground so you can't dig under it,” says James Flanagan, head of JK Flanagan, a small structural construction company based in San Francisco. He says his precast concrete slabs could be put up by crane along the border.

Flanagan is a strong Trump supporter who is critical of what he says is lax immigration enforcement. He says he wants to be involved in building the wall to be part of history.

“So 10-20 years down the road you can say, 'Hey, I was a part of that,' ” Flanagan says.

He says he’s hoping one of the big construction companies that have a better chance of landing a contract for the wall will sub out a little piece to him.

Carolyne Shearer from Alameda is also looking for a small part of the action. She specializes in writing proposals for companies that bid on federal contracts. She signed up on the government's Business Opportunities website, though she doesn't support Trump's wall.

“If he's serious, and he's actually going to try and build this thing, that's going to be an immense amount of work, and you would have to be sort of an idiot not to at least put yourself on the list,” Shearer says.

The wall project appears to be on a very fast track. Proposals are due by next Wednesday. Those selected will then have to construct mockup walls in San Diego.