As a graduate student in linguistics, Globasa's creator, Hector Ortega, had the opportunity to learn about creole languages. By around the year 2000, he had come to the conclusion that a world language with a truly international lexicon and a simpler phonology and grammar than those of Esperanto was actually possible. Many of the features in Globasa are based on or inspired by the most typical features found in creoles, such as their analytic grammar.
By the time Ortega encountered Neo Patwa around 2009 and Pandunia in 2017, he had already developed the following ideas for a hypothetical full-fledged worldlang that didn't sacrifice expressiveness and clarity—in other words, a worldlang that could actually be a better alternative to Esperanto at all levels:
Truly international lexicon
Simple phonology
Simple grammar
Use of cross-linguistic onomatopoeia (source for all of Globasa's onomatopoeic words)
Choosing easily distinguishable function words and avoiding minimal pairs
When Ortega encountered Pandunia in July 2017, it seemed like the closest worldlang to what he was envisioning. The phonology, however, seemed a bit more complex than necessary (particularly the use of voiced and voiceless stops in word-final position), and there were other issues that he felt needed to be addressed, including similar-sounding words, such as the pronouns. After lengthy Facebook discussions with Risto Kupsala (Pandunia's creator) regarding its phonology, Pandunia's phonemic inventory was changed back to a simpler, earlier inventory. Afterwards, upon closer inspection, Ortega realized that Pandunia lacked the necessary morphology and syntax to disambiguate simple sentences, let alone complex sentences. It was around this time, only a few weeks after encountering Pandunia, that he decided to part ways and begin his own project.
As Ortega began developing the project, he realized that the best way to start was with the most difficult part: function words, including grammatical and derivational affixes. In doing so, the first question he had to address was what to do about content words—specifically, whether to go with classless words while relying on syntactic particles (which he assumed would be Pandunia's approach) or to assign word classes and probably use affixes to switch between them. He knew he most definitely did not want to introduce vowel endings, as in Esperanto. This would have represented a clear deviation from the typical creole language model. He opted for a middle ground between the two extremes of the classless-word approach and the vowel-ending approach: adopting two major word classes, noun/verb words and adj/adv words. The reasons for rejecting the classless-word approach are complex and have been discussed with Risto elsewhere.
Ortega initially anticipated spending about one year developing the entire core grammar, at least 500 total word roots and affixes, and a simple website. Instead, it took about that long to decide on the form of all function words and affixes while developing the framework for the core grammar. It took him another year to complete the core grammar, come up with a lexicon of 1,000 roots, and complete the first website, all while continuing to make adjustments and changes. Before publishing, he wanted to be sure the project was at least 95% stable.
The name of the language was originally Geokreol. Later on, Ortega considered Gayabas. Initially, all truncations omitted the final vowel of the root word (basa → bas, for example), but once he decided that truncations need not be systematic, he came up with -sa for naturalistic language names (Espanisa, Fransesa, Turkisa, etc.), which led to the merged root Globasa. Ortega decided to publish Globasa on July 26th, 2019, as a nod to Esperanto, since that was the date in 1887 when the Unua Libro was published. After its publication, more changes and adjustments ended up being made than he had initially anticipated, so it is possible that Globasa was under 95% stable when first published, but certainly not under 90%. See Globasa's Stability.