Explore the intricacies of Ruby's memory optimization in this RubyConf 2021 talk by Peter Zhu and Matt Valentine-House. Delve into Ruby's current memory model, its limitations, and the proposed Variable Width Allocation project. Learn about RVALUE structure, heap page organization, object allocation, garbage collection processes, and CPU cache performance. Discover how moving system heap memory into Ruby heap memory can reduce allocations and improve control over memory layout. Examine different string allocation techniques, size pools, and the impact on Shopify's production environment. Gain insights into methodologies for benchmarking and testing, including railsbench and rdoc generation. Understand the potential benefits and challenges of implementing Variable Width Allocation in Ruby, including object resizing capabilities and RVALUE shrinking.