...

• Indexing and Search
• User Management & Access Controls
• Filtering Search Results by Access Rights
• Scalability, Replication, Redundancy and Failover
• Backups and Disaster Recovery
• Content Modeling and the CMA
• Writing Client Applications for Fedora: Choosing Frameworks, Languages, etc.
• Managing Large Files
• Video
• ORE & Atom
• Workflow (people-based)
• Workflow (service orchestration)

...

Visit the recommended reading, which contains some recommended posts from many of these blogs (this is only updated periodically).

Presentations

• NLM Digital Repository Server Architecture - This presentation is from the Washington, DC Fedora User's Group meeting in January 2011, and describes NLM's server architecture and approach to redundancy, replication and failover in the initial implementation of NLM's repository.