Content expansion roadmap

This file is the durable handoff for repository expansion. Read it with the content authoring standard at the start of every session. It records authoring work, not learner progress.

Authoring handoff

• Active bundle: Wave 4.1 — Software design, coupling, cohesion, SOLID, and pattern-selection trade-offs
• State: Planned; Waves 0–3 complete
• Immediate next action: Inspect engineering/software-design-and-ddd.md, decide whether design and architecture/DDD require a split under the authoring depth standard, and define the first Wave 4 canonical question bundle.
• Relevant files: engineering/software-design-and-ddd.md, interviews/architecture-and-leadership-questions.md, README.md
• Last completed commit: this handoff’s commit (git log -1) — Complete performance bundle and Wave 3

If bundle files are uncommitted, resume them. Preserve unrelated changes. When a bundle is committed, replace this handoff with the next bundle and its first concrete action.

Status key

• Planned: no bundle work has started.
• Active: the handoff names this bundle; resume it after a reset.
• Complete: reference page, canonical questions/answers, sources, validation, roadmap update, and focused commit are all present.

Wave 0 — Authoring foundation

• Add this reset-aware roadmap and the fixed authoring standard.
• Define explicit Outline, Concise draft, and Complete status markers.
• Define stable question IDs and keyed collapsible answer markup.
• Convert the cross-topic question bank to an index and curated mock sets; migrate seed prompts into canonical banks incrementally as each owning bundle is completed.
• Record broad-page splits below so later work does not recreate overlapping content.

Existing seed questions remain unversioned prompts until their owning bundle is completed. The first completed bundle establishes the canonical implementation of the ID and answer contract.

Wave 1 — Laravel interview core

#	Bundle	State	Primary reference
1	Request lifecycle, container, providers, and facades	Complete	laravel/request-lifecycle-container-and-facades.md
2	Routing, middleware, and model binding	Complete	laravel/routing-middleware-and-model-binding.md
3	Validation, authorization, policies, and tenant boundaries	Complete	laravel/validation-authorization-policies-and-tenant-boundaries.md
4	Eloquent model mechanics	Complete	laravel/eloquent-model-mechanics.md
5	Eloquent relationships, loading, and N+1 behavior	Complete	laravel/eloquent-relationships-and-loading.md
6	Testing Laravel applications	Complete	laravel/testing-laravel-applications.md
7	Queues, events, listeners, notifications, and retries	Complete	laravel/queues-events-listeners-notifications-and-retries.md
8	Authentication, Sanctum, Passport, OAuth2, and API security	Complete	laravel/authentication-and-api-security.md
9	Cache, sessions, and Laravel’s Redis integration	Complete	laravel/cache-sessions-filesystem-and-redis.md
10	Filesystem, uploads, and object storage	Complete	laravel/filesystem-uploads-and-object-storage.md
11	Configuration, exception handling, and logging	Complete	laravel/configuration-errors-and-logging.md
12	Artisan commands and scheduling	Complete	laravel/artisan-console-and-scheduling.md
13	Deployment, queue workers, and Octane	Complete	laravel/deployment-and-long-running-workers.md
14	Laravel foundations reconciliation	Complete	laravel/framework-foundations.md; links without duplicating detailed pages

Wave 2 — PHP precision and internals

1. Complete: Type declarations, coercion, variance, readonly state, enums, and static-analysis types.
2. Complete: Object identity, cloning, inheritance, traits, finality, and magic methods.
3. Complete: Functions, closures, callables, capture, named arguments, and generators.
4. Complete: Arrays, keys, comparison, references, JSON shape, and copy-on-write.
5. Complete: Errors, exceptions, shutdown, destructors, and recoverability.
6. Complete: Runtime, zvals, memory, OPcache, JIT, FPM, workers, and Octane.
7. Complete: Composer, dependency resolution, autoloading, standards, and supply-chain concerns.
8. Complete: Modern versus legacy PHP and staged migration reasoning.

Wave 2 ownership has been reconciled: object, array, callable, runtime, error, and Composer mechanisms live in their dedicated pages rather than the type-system page.

Wave 3 — Backend engineering core

1. Complete: Data structures, complexity, and selecting the real bottleneck.
2. Complete: Concurrency, processes, asynchronous I/O, cancellation, and backpressure.
3. Complete: HTTP, DNS, TCP/TLS, proxies, caching, time, and encoding.
4. Complete: API semantics, compatibility, pagination, errors, idempotency, and webhooks.
5. Complete: Relational guarantees, indexes, query plans, transactions, and isolation.
6. Complete: Cache and Redis guarantees, stampedes, leases, eviction, and failure behavior.
7. Complete: Distributed delivery, ordering, outbox, sagas, and reconciliation.
8. Complete: Testing boundaries, doubles, static analysis, mutation testing, and CI.
9. Complete: Application and operational security.
10. Complete: Performance, capacity, saturation, profiling, and scaling decisions.

Wave 3 ownership has been reconciled: concurrency/process scheduling lives in its dedicated page, generic cache guarantees live in engineering/cache-and-redis.md, performance links to those mechanisms instead of duplicating them, and the two canonical interview banks contain answered stable IDs for all ten bundles.

Wave 4 — Senior engineering and leadership

1. Software design, coupling, cohesion, SOLID, and pattern-selection trade-offs.
2. Architecture, DDD, modular monoliths, and service boundaries.
3. Deployment, compatible migrations, containers, rollback, and recovery.
4. Observability, SLOs, alerting, diagnosis, and incident response.
5. Technical leadership, review, estimation, debt, ADRs, and disagreement.
6. System-design method and the booking, webhook, import, tenancy, and notification scenarios.

Absorb engineering/team-practices-and-system-design.md into the leadership and system-design pages, then remove it. Split software design from architecture/DDD if a completed page would exceed the normal depth.

Wave 5 — Optional and synthesis material

1. Frontend knowledge relevant to Laravel interviews.
2. AI-assisted development.
3. Common-confusions reference.
4. Primary-source map and glossary cross-links.
5. Debugging and code-review scenario expansion.
6. Final cross-topic mock-interview sets and navigation audit.

Begin optional material only after the Laravel, PHP, and backend-engineering core is complete.