The private equity firm is expanding into the city by taking space at the upcoming 830 Brickell tower. : Thoma Bravo of Chicago has leased space in Miami’s biggest upcoming office project, as a wave of interest from financial and tech companies offers hope for the city’s struggling office market. The private equity firm has signed up for roughly 36,500 square feet on two floors at 830 Brickell, a 55-story skyscraper under development in the Brickell financial district. OKO Group and Cain International are developing the prime, 640,000-square-foot property, which is slated for completion next year.