Humble Tech Book Bundle: Software Architecture by O'Reilly (humblebundle.com)

I would highly recommend getting the $25 bundle. It has a great set of titles:

- Building Event-Driven Microservices

- Building Evolutionary Architectures

- Building Micro-Frontends

- Continuous API Management

- Flow Architectures

- Foundations of Scalable Systems

- Fundamentals of Software Architecture

- Learning Domain-Driven Design

- Mastering API Architecture

- Microservices Up and Running

- Monolith to Microservices

- Software Architecture Metrics

- Software Architecture: The Hard Parts

- The Art of Agile Development

- The Software Architect Elevator