Migration
33 bites tagged Migration: interview questions with model answers, and 60-second explainers.
Test yourself: Top 30 Migration interview questions →Multiple choice, with the correct answer and why it is correct on every question. Free, no sign-in.Cloudflare uses AI to map cryptography for its post-quantum migration
Cloudflare describes using an internal tool, CryptoLabe, to discover cryptography across its code and plan a 2029 post-quantum migration.
What do the spec file and CodeGen do in migration?
The spec file declares the component's typed props and events; CodeGen reads it at build time to generate type-safe C++/native and JS glue, catching mismatches early.
Decommission a depended-on API gracefully
Map consumers and usage, provide a migration target, announce a versioned timeline, decommission only after traffic hits zero.
Build the case to deprecate a legacy feature
Quantify cost versus value and who the 2% are, propose migration paths and a phased sunset, weigh velocity against trust.
Automating a breaking design token rename
Ship a codemod to rewrite old token references, add a deprecation alias mapping old to new during a transition window, document the change.
Deprecating a widely used component gracefully
Announce and document replacement, soft-deprecate with runtime and type warnings, ship codemods, remove only in a later major.
Challenges of breaking changes in a design system
Technical (semver, codemods, coexistence) and organizational (comms, migration support, timelines) challenges.
Coexisting major versions during migration
Scoped aliases or namespaced packages, isolated token scopes, and incremental migration.
Quantifying migration cost for a major release
Pre-release, scan codebases for affected usages and estimate engineer-hours; post-release, track actual upgrade lead time and effort.
Designing a component deprecation process
Announce with a replacement and timeline, mark deprecated with runtime and lint warnings, provide codemods, then remove only in a major release.
Zero-downtime schema migration on a hot table
Expand-migrate-contract phases, dual-write and backfill, decouple deploys from migrations.
Near-zero-downtime database migration to cloud
Assess and provision, do a full load then continuous CDC replication with a tool like DMS, validate, then cut over with a rollback plan.
Driving and measuring design system adoption
Lower friction with migration paths and great docs, incentivize over mandate, and measure adoption via package usage, component coverage, and code analysis.
Releasing a breaking Button change with SemVer
Bump the major version, write a changelog and migration guide, deprecate before removing where possible, and communicate clearly.
Structuring release notes for breaking API changes
Lead with a summary and why, group breaking changes with before/after migration steps, give deprecation timelines and an upgrade path.
Strangler Fig with serverless and an event bus
API Gateway acts as the routing facade, new features run as Lambda functions, an event bus decouples and fans out to new services, and traffic shifts feature by feature until the monolith…
Explain the Strangler Fig pattern
A facade routes traffic, new services gradually replace legacy features one slice at a time, and the old system is retired when fully strangled.
Migrating a stateful monolith to PaaS
Externalize state to backing services, make processes stateless and disposable, read config from the environment per Twelve-Factor.
End-to-end process for a Modal props API break
Justify and design the change, additive rollout with deprecation, major release plus codemod, comms and adoption tracking.
Gradual design system adoption in legacy code
Coexistence strategy, codemods for mechanical swaps, lint rules to block regressions, prioritize high-traffic surfaces.
Technical and comms plan for a Button break
Additive-first then deprecate, major semver, codemod and guide, multi-channel early comms with adoption tracking.
Critical a11y fix requiring a breaking API change
Ship a safe interim fix, plan the breaking API as a major with deprecation and codemod, communicate urgency.
Rolling out a breaking change to a shared Button
Major semver bump, deprecation period, codemod and migration guide, staged comms.
Unify Android EventBus and RxJava with Kotlin Flow
Mixing EventBus, RxJava, and Kotlin Flow in Android codebases creates memory leaks and GC pressure from stream wrapping. Operator translation and lifecycle mismatches drive engineering debt.
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