1. 1. Integration Services: AWS CodePipeline offers seamless integration with other AWS services such as AWS CodeCommit, AWS CodeBuild, and AWS CodeDeploy, allowing for a complete DevOps solution within the AWS ecosystem. In contrast, TeamCity is a standalone build management and continuous integration (CI) tool that can integrate with various code repositories, build tools, and deployment platforms, regardless of the cloud provider or architecture being used.

2. 2. Cloud-based vs On-premises: CodePipeline is a cloud-based CI/CD service provided by Amazon Web Services (AWS), which means it is fully managed and hosted by AWS. On the other hand, TeamCity is an on-premises solution that needs to be installed and maintained on a local server or infrastructure, providing more control but requiring additional effort for setup, maintenance, and upgrades.

3. 3. Scalability and Elasticity: AWS CodePipeline is designed to automatically scale and handle large-scale CI/CD pipelines and workloads, utilizing the vast resources of the AWS cloud infrastructure. In contrast, TeamCity's scalability and elasticity depend on the capacity of the on-premises infrastructure, which may require additional hardware or configuration changes to handle increased workloads.

4. 4. Platform and Language Support: AWS CodePipeline is mainly focused on supporting AWS services, but it can also integrate with various third-party tools and systems to provide flexibility for application development pipelines. TeamCity, on the other hand, is known for its extensive platform and language support, allowing developers to build, test, and deploy applications written in different programming languages and targeting different platforms.

5. 5. Cost Structure: AWS CodePipeline follows a pay-as-you-go pricing model, where users are billed based on their actual usage of the service, taking into account factors such as the number of pipeline executions, storage, and data transfer. In contrast, TeamCity has a fixed licensing model based on the number of user licenses or server licenses, which may be more suitable for organizations with predictable workloads and budget planning.

6. 6. Managed Service vs Self-management: AWS CodePipeline is a fully managed service, handling infrastructure provisioning, security, and updates, allowing developers to focus on their code and CI/CD workflows. However, TeamCity requires self-management, which involves tasks such as installing updates, managing security, and configuring the server to meet specific needs.

In summary, AWS CodePipeline provides seamless integration with AWS services, offers scalability in the cloud, and follows a pay-as-you-go pricing model, while TeamCity is an on-premises solution with extensive platform and language support, a fixed licensing model, and requires self-management.