Being the CEO of one of the world's biggest tech companies can bring unimaginable pressures, so imagine what being the Chief Executive Officer of two industry giants must entail. As the CEO of both Twitter and payments company Square, Jack Dorsey has the herculean task of managing both these multi-billion dollar firms. In a recent Q&A session with online forum Product Hunt, he revealed how he does it.

Dorsey says he has a secret to keep from being overwhelmed: "I look to build a lot of consistent routine. Same thing every day. Allows a steady state that enables me to be more effective when I do have to react to something out of band."

As you would expect from someone in his position, Dorsey works up to 18 hours a day. When responding to questions about his daily routines, he said he sleeps from 11 pm to 5 am, and then meditates for 30 minutes. The meditation is followed by a 20-minute workout and coffee before he starts his working day, which is usually spent at Twitter in the morning and then at Square in the afternoon.

When asked what he looks for in potential employees, Dorsey said that passion is the attribute he valued most. "I look for passion. Only thing that can't be taught. Why Square? Why Twitter? If I hear passion for the purpose in the answer, then I look for leadership and skill. Passion and purpose and principles first though!"

Dorsey's isn't the first big-name from the tech world to hold dual CEO positions. Steve Jobs famously ran Apple and Pixar Animation Studios while they were both publicly traded, and Elon Musk is CEO of both Tesla and aerospace manufacturer SpaceX. Musk once said he wouldn't recommend running two companies as it "really decreases your freedom a lot."

Even though Dorsey appears to be handling his two roles well, he must surely be feeling the pressure as both companies' shares underperform. Despite Twitter revenue rising this year, its share price has fallen to an all-time low of around 16% since Dorsey was appointed full-time CEO. And while Square's shares have risen around 36% since the IPO last month, they still trade below the price private investors paid last year.