For the first two seasons of Deep Space Nine, stories requiring characters to travel off-station typically involved small runabout vessels.

The Defiant was initially designed by art illustrator Jim Martin, with contributions from visual effects supervisor Gary Hutzel and modelmaker Tony Meininger.

[1] An early screenplay for Star Trek: First Contact (1996) called for the Defiant to be destroyed, but Behr objected and the idea was dropped.

It appears briefly in Star Trek: First Contact under the command of Worf where it's left badly damaged and the crew has to evacuate to the Enterprise-E after life support fails.

The Defiant is seen briefly in the Star Trek: Picard third season episode "The Bounty", out of commission and docked at Starfleet's Fleet Museum.

The USS Defiant is noted as a powerful spacecraft vessel of the Star Trek science fiction universe in the late 24th century.