Before Twitter boasted a market cap of 22.1 billion, had 336 million monthly active users and became the preferred mode of communication for President Donald Trump, it started with a sketch on a legal pad.
On Tuesday, Twitter posted a photo of co-founder Jack Dorsey's illustration of how the platform might work, with the caption, "@Jack's very first drawing of us back in 2005. Love ya, Dad!"
In the drawing, Twitter has a box for the user's status (such as "reading," "in bed," or "going to the park"), as well as inputs for the user's name, phone number and email address.
But the photo of the sketch is not the first look back at early Twitter users have seen. In April, co-founder Biz Stone, tweeted a throwback photo of Twitter's first office, which it occupied until 2008.
Indeed, not only has the platform's tech come a long way since Dorsey's 2005 sketch, but the company's offices have too.
Today, Twitter boasts 35 global offices, many in glamorous locations such as Dubai, London, New York City and Paris. The offices, according to the company, "reflect the regional and cultural spirit of the cities they're in." For example, in Atlanta, the conference rooms are named after southern hip hop icons (such as CeeLo Green and Andre 3000) and Sydney's office features a panoramic view of the city and its harbor.
The offices also include features such as a coffee bar that offers custom-designed lattes, on-tap brews, trendy décor and colorful murals by local artists.
But in 2006, Twitter, founded by Dorsey, Stone, Evan Williams and Noah Glass, got its start in offices at 164 South Park Avenue in San Francisco, in offices "where the only sources of natural light were the two skylights and small-block glass windows," according to Inc.
The photos below, provided to CNBC Make It by Stone, were taken of that space in March 2008. In January of that year, Twitter had only eight employees, according to its blog. Previous tenants of the 6,400-square-foot space include Instagram.
The photos below, also from Stone, showcase another early Twitter office, and were taken in July 2008. The building, located at 539 Bryant Street, served as one of Twitter's first headquarters in San Francisco. In 2013, the 55,000-square-foot building sold for $35.2 million, or $630 per square foot, according to the San Francisco Business Times.
Though the pictures portray a far different setting from Twitter's current swanky offices, there is a start-up office staple in one photo: A foosball table.
This is an updated version of a previously published article.
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This story has been updated.