Catherine O'Neill (26) set up her civil engineering firm, Amelio, in 2012 while she was still studying at university.
Now her business employs more than 50 people across the Republic and Northern Ireland.
She was recently nominated for an EY Entrepreneur of the Year Award, becoming the youngest woman to ever be short-listed.
"I graduated from Queen's University Belfast at the height of the recession, when there were zero graduate jobs in civil engineering," she says. "Most of my classmates left Ireland. They went to Dubai or Australia, where there was work. But that wasn't an option for me, I just did not want to move.
"So I decided to become my own employer. I started my business, originally named One Environment, in my parents' house.
"In the beginning it was just me, a classmate and a small piece of equipment. We did anything that we could find, even if it wasn't the type of work I was looking to do - no job was too small."
In the four years since, Amelio has grown to more than 50 people, with a turnover of €3m.
"Unlike most of our competitors, we are a one-stop shop for civil engineering projects," says O'Neill.
"We do a lot of work in drainage repair, high-pressure cleaning, pollution treatment and sewer cleansing, including CCTV drainage inspection surveys.
"We are self-funded, and I still own 100pc of the business.
"Clients include one of the country's largest utility companies and county councils.
"One of our key pillars is that Amelio takes a 'no-dig' approach - we advocate drainage solutions that solve problems without digging up the ground and disturbing traffic and the environment.
"I want Amelio to be the biggest drainage solutions company in Ireland and the UK.
"We have offices in Dublin and Belfast and last year bought a company in Gloucestershire.
"I'm also actively looking for other locations to establish Amelio. There's a lot of ground to gain in the UK and Ireland, a lot of room for expansion, but eventually I would like to go farther afield.
"I have definitely noticed an uplift in the domestic construction and civil engineering industry. You can see it just by walking around Dublin - building has begun again.
"Thankfully, Amelio is benefiting from this, but profit margins remain tight, so we are constantly looking for ways to do things more efficiently and in a more cost-effective manner.
"We have doubled turnover every year since our founding and intend to maintain that pace of growth.
"But I want to have a back-up plan, so I'm studying at the weekends to be a chartered accountant, which is also helping me to stay on top of the financial side of the company.
"I'm particularly proud of our staff. I built up a fantastic team.
"We have a very high proportion of civil engineers relative to our size. It's a pleasure to be able to keep civil engineers at home rather than see them leave the Republic and Northern Ireland for Dubai and Australia."