What gets stored, what gets recomputed, what becomes stale, and how the system knows.
3 parts
A measured diagnostic tree for slow Rust builds: cargo --timings for the shape, the fingerprint log for unexpected rebuilds, -Ztime-passes for the phase inside one crate, and what splitting a workspace into more crates actually changes.
Evidence: experiments/rust-atlas/build-times/
Rust's incremental cache is a dependency graph, not a saved compiler process. Learn what an edit dirties, how green nodes are recovered, and why Cargo may still run rustc.
A practical model of rustc queries, providers, memoization, dependency tracking, cycles, and red-green incremental reuse.
When you sync two systems with webhooks, the copy slowly becomes wrong: some events are lost, some are duplicated, some arrive in the wrong order. Reconciliation is the way to make the two systems agree again. Here is how to design an API for it.
Cargo build scripts are cached from declared file and environment inputs. Use rerun-if rules, verbose evidence, and a rebuild matrix to remove accidental rebuilds.
Concrete simulations of the records a timestamp cursor can miss, plus safer tuple cursors, overlap windows, change logs, and reconciliation.
A state-machine walkthrough for joining a full snapshot with live changes without gaps, stale overwrites, or false deletions.
A concrete Cargo dependency graph showing when features unite across workspace packages and when host, target, and platform edges stay separate.
Rust 1.97 lets Cargo deny cached lint warnings without rebuilding crates under different RUSTFLAGS. Here is the behaviour and the migration path.
A tested walkthrough of monomorphization collection, concrete generic instances, codegen-unit partitioning, compile-time parallelism, and binary-size trade-offs.
An exact overlap-window synchronization algorithm with tuple ordering, idempotent application, atomic checkpoints, and repair for unbounded lateness.
Mutation simulations showing how offset, keyset, and cursor pagination behave when records are inserted, deleted, or updated during a long API scan.
A dual-read timeline for importing historical data while live updates continue, without gaps or stale snapshot rows overwriting newer events.
A correction-first design for late data using event time, watermarks, affected-window replay, versioned aggregates, and explicit finality.
Cargo resolver 3 prefers dependency releases compatible with your declared rust-version. See where fallback helps, where it cannot, and how workspaces change the result.
A concrete schema and concurrency model for mapping external IDs to internal entities without duplicates, cross-tenant collisions, or unsafe retries.
A practical comparison of conflict policies that preserve business intention when two synchronized systems edit the same entity.
A practical field-ownership matrix for deciding which system may write each value before loops, silent overwrites, and deletion conflicts enter a bidirectional sync.
A lossiness ledger and test strategy for keeping a useful canonical model without silently erasing provider-specific meaning.
Schema validation catches only part of provider drift. Test the fields, behaviours, and semantic mappings your consumer actually depends on, then verify them safely.
An adapter contract and test suite for translating provider pagination, identity, nulls, versions, errors, retries, deletion, and capabilities—not only field names.
Third-party APIs should not become your product model. Learn how a stable internal representation contains provider changes and keeps integrations understandable.
API schema changes are not only field changes. Separate source contracts from product meaning, preserve evidence, and evolve mappings without spreading breakage.
Older, introductory or narrower pieces on the same subject.