boundaries

Gary Bernhardt's RubyConf 2012 talk on testing in isolation without mocking everything. It goes through behavior versus data, mutation versus immutability, and how a functional core with an imperative shell yields natural isolation and parallelism.

Robert C. Martin (Uncle Bob) presents the principles of Clean Architecture, covering dependency direction, boundaries, and why frameworks and databases should be details rather than the center of an application.

Richard Cook's short Velocity 2013 talk on resilience in complex adaptive systems, arguing systems operate near the edge of failure and that the surprise is how rarely they fail. He presents a model of how pressures push systems toward failure boundaries.

Robert C. Martin's Ruby Midwest 2011 keynote argues that software architecture should express the application's intent rather than its framework. He covers separating entities, interactors and boundaries so the web, database and framework are details.

A Vsauce video exploring whether chairs exist, through metaphysics, mereology and the philosophy of categorizing objects. It runs about 38 minutes and cites academic work on ontology.

J. B. Rainsberger argues that large integrated tests are a scam: they are slow, fail opaquely, and give a false sense of coverage. He advocates focused collaboration and contract tests at boundaries instead.

Ian Piumarta's 2007 Stanford EE380 lecture on building a dynamic programming environment from the ground up, from the Viewpoints Research Institute's work. It covers the design of a language and system with a recursive design, parsing through code generation, and the COLA architecture.