Google Cloud Functions, AWS Lambda, and Azure are major serverless services that offer a range of features, pricing options, and developer experiences. Pricing is an important factor, with Google providing twice as many free requests but doubling the cost for additional requests. Features such as APIs, integrations, and support for various languages play a crucial role in choosing the right service. Developer experience is also vital, with Google Cloud Functions aiming to simplify the process, while Azure offers multi-language support and extensive documentation. Reliability and scalability are essential, with all three services offering SLAs and guarantees. Choosing the right provider requires careful consideration of business needs, growth plans, and long-term implications. By selecting the right serverless service, developers can achieve rapid scaling and growth for their AI voice apps.