Writer, the AI writing assistant for professional users, announced today a $21 million Series A funding round as the company transforms the way people write. The financing was led by New York-based global private equity and venture capital firm Insight Partners with a slew of top machine learning experts, SaaS operators, writers, and CEOs participating, including Gradient Ventures, the Todd & Rahul Angel Fund, Scott Belsky, Oliver Jay, Jack Altman, Allison Pickens, Packy McCormick, Lenny Rachitsky, Austin Rief, Ankur Nagpal, Alex MacCaw, Camille Ricketts, Vivek Sodera, Julia Lipton, and James Beshara. The funding will be used to invest in product, engineering, and GTM hiring.