Nearly six months after raising $19 million in an initial public offering, One Stop Systems Inc. (Nasdaq: OSS) is expanding its headquarters in Escondido by more than one-third.

The company signed a six-year lease that expands its design, manufacturing and test facilities by 6,121 square feet, bringing its total space to more than 24,000 square feet.

One Stop Systems, which was founded in Escondido in 1998, makes high performance computing systems and the software needed to operate such systems.

CEO Steve Cooper said the expansion was prompted by rapid growth and an anticipated increase in "design wins" over the coming months.

He also said the additional space will allow the company to consolidate its San Diego operations and thereby reduce operational costs.

The company made its public debut on the Nasdaq exchange in February.

Reach reporter Sarah de Crescenzo at sarahd@sdbj.com.