Ada, accompanied by her mother, visits Charles Babbage and sees his Difference Engine. This encounter sparks her fascination with mechanical computation.

Ada translates an article by Italian military engineer Luigi Menabrea about Babbage's Analytical Engine. She adds extensive notes to the translation, which are significantly longer and more detailed than the original article.

Ada's translation and notes are published in Taylor's Scientific Memoirs. Her notes contain what is now recognized as the first algorithm intended to be processed by a machine – specifically, an algorithm to compute Bernoulli numbers. This earns her recognition as the first computer programmer. She also speculates about the potential of the Analytical Engine to compose elaborate music and produce complex graphics.

While Ada remained interested in Babbage's work, financial troubles and her failing health limited her active participation in his projects. She continued correspondence with Babbage, but their collaboration diminished.