When choosing a SaaS application development company, key factors to consider include expertise in relevant technologies and frameworks, a proven track record of successful projects, and the ability to deliver scalable and secure solutions.

Additionally, evaluate the company's client testimonials, customer support, and post-launch services to ensure a reliable, long-term partnership.

Effective communication and understanding of your business needs are also crucial to ensuring the development process aligns with your goals and expectations.

Lastly, consider their pricing structure and flexibility to accommodate future growth and changes.