Serverless development offers numerous benefits, with cost efficiency being a primary advantage. By choosing the right tool for the task, developers can save money and optimize their architecture. In the case of Lumigo's data processing flow, the team initially chose Kinesis Streams due to its real-time processing capabilities and scalability features. However, as the company grew and data volumes increased, the cost of Streams became too high, prompting a reevaluation of the decision. After analyzing the costs and benefits of both Streams and Firehose, Lumigo decided to switch to Firehose, which offered significant cost savings, improved scalability, and reduced latency. By utilizing both services together, the team achieved a balance between real-time processing and cost efficiency, demonstrating the importance of careful consideration when making serverless architecture decisions.