In this step, you need to define the scope of your SaaS product by understanding the problem it aims to solve and identifying the target audience. Prioritize feature development based on their importance and complexity, focusing on creating a Minimum Viable Product (MVP) for a quick launch. Ensure your opinionated tech stack aligns with the product requirements, considering factors such as scalability, performance, security, and developer familiarity for frontend, backend, and database technologies.

During this phase, start by implementing the frontend using your chosen technologies, ensuring a responsive, intuitive, and visually appealing user interface. Set up the backend infrastructure, developing APIs and business logic to handle user requests and data processing while focusing on scalability. Design the database schema to match application data requirements, integrating it with the backend for efficient data storage and retrieval, with special emphasis on data security. Lastly, perform comprehensive testing, including unit tests, integration tests, and end-to-end testing, using automation to ensure a high-quality product and smooth deployment.

In this final phase, with AWS as our selected and reliable tech stack, we move towards scalability and automation. Automate the deployment process through a CI/CD pipeline, ensuring quick and frequent updates for a seamless user experience. Set up monitoring tools to track performance and usage, optimizing the application's speed and efficiency on AWS. Implement robust security measures to safeguard user data, while regularly updating dependencies to prevent vulnerabilities. Post-launch, offer excellent customer support, promptly addressing user inquiries and feedback. We will continuously iterate and improve the product based on user input to enhance its value and market fit, leveraging the capabilities of AWS for our project's success.