Track 12 of 12 · Move changes safely
Data, APIs & Delivery
Connect storage guarantees, API boundaries, version-control history, and automated integration. Learn what each layer promises and where correctness still belongs to the application.
Ten concepts, in learning order
Each lesson assumes the ideas above it and prepares you for the ones below.
- 01Database transaction and ACIDA database transaction groups operations into a commit or rollback boundary; ACID summarizes atomicity, consistency, isolation, and durability properties provided under the database's documented guarantees.
- 02Database indexA database index is an auxiliary data structure that orders or organizes selected values so qualifying rows can be located without scanning the entire table.
- 03Caching and LRU evictionA cache stores reusable results closer to demand; an LRU policy evicts the entry whose most recent access is oldest when bounded capacity needs space.
- 04Strong and eventual consistencyHere, strong consistency means linearizability: operations fit one real-time-respecting single-copy order. Eventual consistency permits temporary divergence but promises replicas converge if updates stop and communication continues.
- 05Throughput vs latencyLatency is the elapsed time for an individual operation, while throughput is the number or amount of operations completed per unit time.
- 06HTTP API and REST semanticsAn HTTP API exchanges resource representations through standardized request methods, status codes, headers, and caching semantics; REST is an architectural style whose constraints go beyond using JSON over HTTP.
- 07Serialization and JSONSerialization converts in-memory data into a transportable or storable representation; JSON represents objects, arrays, strings, numbers, booleans, and null as Unicode text with a defined grammar.
- 08Git commitA Git commit is an immutable history object that records a project tree, parent commit references, author and committer metadata, and a message; its object ID is derived from its content.
- 09Git branches and mergesA Git branch is a movable name pointing to a commit; merging integrates histories by fast-forwarding when one tip is an ancestor or by creating a combined result from divergent parents.
- 10Continuous integrationContinuous integration is the practice of integrating small changes frequently and automatically building and testing each candidate revision in a clean, repeatable environment.