EC2 or Amazon Lightsail (VPS) for my project

Based on your requirements, Amazon Lightsail could be a suitable option for your project, but there are some considerations to keep in mind.

Lightsail is designed for simpler workloads, quick deployments, and getting started on AWS. It offers a user-friendly interface, includes a static IP address, and provides automatic backups and snapshots. For your docker-based application with multiple microservices, Lightsail does offer container deployments, which could be beneficial.

Performance-wise, Lightsail instances are engineered for web servers, developer environments, and small database use cases. They use burstable performance instances, providing a baseline level of CPU performance with the ability to burst above the baseline when needed. This could be sufficient for your lightweight application without GPU requirements.

Regarding security, Lightsail provides basic security features, but it may not offer the same level of advanced security options as EC2. You'll need to ensure that your application's security requirements can be met within Lightsail's capabilities.

In terms of stability, Lightsail is a managed service, which means AWS handles many of the underlying infrastructure concerns. However, it's important to note that Lightsail has some limitations compared to EC2, particularly in terms of scalability and integration with other AWS services.

If your user traffic starts to increase significantly, you might face limitations with Lightsail. While it does offer load balancing, the scalability options are not as extensive as what you'd find with EC2. If you anticipate rapid growth or need advanced networking features, EC2 might be a better long-term solution.

Pros of Lightsail include its simplicity, predictable pricing, and ease of use for smaller projects. It's a good option if you want to get your application up and running quickly without dealing with the complexities of EC2.

Cons include limited scalability, fewer instance types to choose from, and potential difficulties if you need to integrate with more advanced AWS services in the future.

Given your experience with EC2 and the complexity of your application (multiple microservices, CI/CD pipelines), you might find that EC2 provides more flexibility and room for growth. However, if you want to start small and potentially migrate to EC2 later if needed, Lightsail could be a good starting point.

Remember, you can always start with Lightsail and migrate to EC2 later if your needs outgrow Lightsail's capabilities. The choice ultimately depends on your specific requirements, expected growth, and how much control you need over your infrastructure.
Sources
Amazon Lightsail, AWS Elastic Beanstalk, or Amazon EC2?
Amazon Lightsail, AWS Elastic Beanstalk, or Amazon EC2? - Amazon Lightsail, AWS Elastic Beanstalk, or Amazon EC2?
Instances - Amazon Lightsail
Key considerations when using AWS for web hosting - Web Application Hosting in the AWS Cloud