# noCV engineering task library Content version 5 Fictional engineering practice briefs. Starter repositories, fixtures, automated grading, and verified ownership are not included. Tests, patches, and runbooks are requested deliverables. They become Outcome Evidence only through a qualified Mission and immutable Evidence IDs. Independent adaptation must be observed under a declared verification policy and cite immutable Evidence IDs. Completing a planning ticket establishes no Ownership Evidence. ## DPREVIEW — Create review environments that clean themselves up A fictional product team creates local preview environments for pull requests. Names collide, fixtures copy more data than needed, failed provisioning leaks resources, and merged changes leave previews running. Build an infrastructure simulator with fake DNS, storage, and deployment providers; no cloud account or live domain is supplied. **Field:** DevOps. **Suggested stack:** TypeScript, Infrastructure model, Fake DNS, Queue adapter. **Engineer value:** Practice ephemeral environment lifecycle, scoped configuration, cleanup, quotas, and provider reconciliation. **Company value:** Review changes in isolated representative environments while controlling leakage, resource growth, and abandoned infrastructure. **Delivery agreement:** Ten linked tickets across three phases. Use a local repository and fake providers; deliver workflow code, failure tests, a rollback rehearsal, and a concise runbook. ### Setup prerequisites - Resource graphs - Idempotency - Tenant isolation ### Make the delivery contract visible Replace implicit workflow assumptions with reviewable inputs and outcomes. #### DPREVIEW-101 — Derive a collision-resistant preview identity **Task · Medium priority · Foundational** noCV practice brief v5 · DPREVIEW-101 · Create review environments that clean themselves up Fictional engineering practice briefs. Starter repositories, fixtures, automated grading, and verified ownership are not included. Phase: Make the delivery contract visible. Depends on: No preceding ticket. Difficulty: Foundational. Estimated focused work: 90 minutes; setup and prerequisite tickets are additional. Estimated field mix: DevOps 70% · Cloud infrastructure 30%. Field percentages are editorial estimates of the ticket's engineering focus. They total 100%; they are not measured time, proficiency scores, or ownership evidence. Two repositories both open pull request 42 and receive the same environment name, causing one preview to replace the other. Acceptance criteria - Identity binds repository, immutable revision, and pull-request identity - Human-readable alias maps to one immutable environment ID - Length and character limits are enforced before provider calls Implementation constraints - Do not use branch text as the sole authority or resource identity. Verification - Create previews for same-number requests in two repositories. - Use oversized and normalization-colliding names and confirm no resource mutation. Deliverables - Preview identity contract and collision tests Rollout and recovery: Adopt IDs in state first while retaining old aliases for display. Project prerequisites: Resource graphs Idempotency Tenant isolation Engineer value: Practice ephemeral environment lifecycle, scoped configuration, cleanup, quotas, and provider reconciliation. Company value: Review changes in isolated representative environments while controlling leakage, resource growth, and abandoned infrastructure. AI tools are welcome during implementation. Record assumptions, review the result, and verify its behavior. Planning status does not create Outcome Evidence or Ownership Evidence. #### DPREVIEW-102 — Compile a minimal preview configuration **Bug · Medium priority · Foundational** noCV practice brief v5 · DPREVIEW-102 · Create review environments that clean themselves up Fictional engineering practice briefs. Starter repositories, fixtures, automated grading, and verified ownership are not included. Phase: Make the delivery contract visible. Depends on: DPREVIEW-101. Difficulty: Foundational. Estimated focused work: 90 minutes; setup and prerequisite tickets are additional. Estimated field mix: DevOps 60% · Security 40%. Field percentages are editorial estimates of the ticket's engineering focus. They total 100%; they are not measured time, proficiency scores, or ownership evidence. Preview inherits production-like integrations and tries to send fixture events to undeclared external endpoints. Acceptance criteria - Preview configuration selects only fake or explicitly allowed providers - Network policy defaults to deny and lists required local dependencies - Secrets are references to preview-scoped fixtures Implementation constraints - No production credential, customer data, or public callback is permitted. Verification - Compile a preview using only declared fake providers. - Reference an external endpoint and a production-like secret scope, then block compilation. Deliverables - Preview configuration policy and denial tests Rollout and recovery: Require policy compilation before any resource plan. Project prerequisites: Resource graphs Idempotency Tenant isolation Engineer value: Practice ephemeral environment lifecycle, scoped configuration, cleanup, quotas, and provider reconciliation. Company value: Review changes in isolated representative environments while controlling leakage, resource growth, and abandoned infrastructure. AI tools are welcome during implementation. Record assumptions, review the result, and verify its behavior. Planning status does not create Outcome Evidence or Ownership Evidence. #### DPREVIEW-103 — Plan the resource graph before creating anything **Story · Medium priority · Intermediate** noCV practice brief v5 · DPREVIEW-103 · Create review environments that clean themselves up Fictional engineering practice briefs. Starter repositories, fixtures, automated grading, and verified ownership are not included. Phase: Make the delivery contract visible. Depends on: DPREVIEW-101, DPREVIEW-102. Difficulty: Intermediate. Estimated focused work: 150 minutes; setup and prerequisite tickets are additional. Estimated field mix: DevOps 60% · Cloud infrastructure 40%. Field percentages are editorial estimates of the ticket's engineering focus. They total 100%; they are not measured time, proficiency scores, or ownership evidence. Provisioning creates storage before discovering the requested database class exceeds the preview quota, leaving an orphan. Acceptance criteria - Plan resolves complete dependency graph and quota cost - Validation lists every blocking reason before mutation - Plan has immutable revision used by apply Implementation constraints - Fake provider discovery is read-only and bounded. Verification - Plan a valid preview and reconcile its declared resource order. - Exceed compute and storage quotas together and confirm zero creates. Deliverables - Preview planner and multi-error quota tests Rollout and recovery: Expose plan-only operation before apply is enabled. Project prerequisites: Resource graphs Idempotency Tenant isolation Engineer value: Practice ephemeral environment lifecycle, scoped configuration, cleanup, quotas, and provider reconciliation. Company value: Review changes in isolated representative environments while controlling leakage, resource growth, and abandoned infrastructure. AI tools are welcome during implementation. Record assumptions, review the result, and verify its behavior. Planning status does not create Outcome Evidence or Ownership Evidence. ### Control change and failure Add bounded concurrency, authority checks, and restart-safe transitions. #### DPREVIEW-104 — Apply preview resources idempotently after interruption **Chore · Medium priority · Intermediate** noCV practice brief v5 · DPREVIEW-104 · Create review environments that clean themselves up Fictional engineering practice briefs. Starter repositories, fixtures, automated grading, and verified ownership are not included. Phase: Control change and failure. Depends on: DPREVIEW-103. Difficulty: Intermediate. Estimated focused work: 150 minutes; setup and prerequisite tickets are additional. Estimated field mix: DevOps 60% · Distributed systems 40%. Field percentages are editorial estimates of the ticket's engineering focus. They total 100%; they are not measured time, proficiency scores, or ownership evidence. Provisioning stops after database creation. Retry creates a second database because local state was not saved before the provider call. Acceptance criteria - Each resource has deterministic operation identity - Apply reconciles provider state before create - Completed resources resume without recreating or skipping dependencies Implementation constraints - Provider calls execute outside state transactions and return untrusted observations. Verification - Apply a complete plan and replay it without changes. - Interrupt after one accepted create and confirm retry adopts the matching resource. Deliverables - Idempotent preview applier and interruption drill Rollout and recovery: Limit concurrent previews while reconciliation behavior is observed. Project prerequisites: Resource graphs Idempotency Tenant isolation Engineer value: Practice ephemeral environment lifecycle, scoped configuration, cleanup, quotas, and provider reconciliation. Company value: Review changes in isolated representative environments while controlling leakage, resource growth, and abandoned infrastructure. AI tools are welcome during implementation. Record assumptions, review the result, and verify its behavior. Planning status does not create Outcome Evidence or Ownership Evidence. #### DPREVIEW-105 — Seed representative data without copying customer records **Task · High priority · Advanced** noCV practice brief v5 · DPREVIEW-105 · Create review environments that clean themselves up Fictional engineering practice briefs. Starter repositories, fixtures, automated grading, and verified ownership are not included. Phase: Control change and failure. Depends on: DPREVIEW-102, DPREVIEW-104. Difficulty: Advanced. Estimated focused work: 240 minutes; setup and prerequisite tickets are additional. Estimated field mix: DevOps 60% · Privacy engineering 40%. Field percentages are editorial estimates of the ticket's engineering focus. They total 100%; they are not measured time, proficiency scores, or ownership evidence. A convenient preview script proposes copying a small slice of the production-like database, including free-text notes. Acceptance criteria - Seed generator produces synthetic entities matching declared schema constraints - Relationships and edge cases are deterministic from a versioned seed - No source connector for customer data exists in preview composition Implementation constraints - Do not claim synthetic distributions reproduce real customer behavior. Verification - Seed two previews with the same revision and compare logical fixtures. - Attempt to configure an undeclared source connector and fail before data access. Deliverables - Synthetic preview seeder and schema-edge fixtures Rollout and recovery: Review fixture usefulness separately from data-safety enforcement. Project prerequisites: Resource graphs Idempotency Tenant isolation Engineer value: Practice ephemeral environment lifecycle, scoped configuration, cleanup, quotas, and provider reconciliation. Company value: Review changes in isolated representative environments while controlling leakage, resource growth, and abandoned infrastructure. AI tools are welcome during implementation. Record assumptions, review the result, and verify its behavior. Planning status does not create Outcome Evidence or Ownership Evidence. #### DPREVIEW-106 — Publish the preview URL only after identity-aware readiness **Bug · High priority · Advanced** noCV practice brief v5 · DPREVIEW-106 · Create review environments that clean themselves up Fictional engineering practice briefs. Starter repositories, fixtures, automated grading, and verified ownership are not included. Phase: Control change and failure. Depends on: DPREVIEW-104, DPREVIEW-105. Difficulty: Advanced. Estimated focused work: 240 minutes; setup and prerequisite tickets are additional. Estimated field mix: DevOps 70% · Networking 30%. Field percentages are editorial estimates of the ticket's engineering focus. They total 100%; they are not measured time, proficiency scores, or ownership evidence. The bot posts a URL when the load balancer responds, but it points to an older preview that still owns the recycled alias. Acceptance criteria - Readiness proves environment ID, revision, schema, and seed version - URL publication compares alias ownership immediately before update - Failure remains pending or failed with exact dependency status Implementation constraints - Use fake DNS and loopback probes; no public record is created. Verification - Publish a ready matching preview alias. - Return healthy content from an older environment and block publication. Deliverables - Identity-aware readiness gate and stale-alias test Rollout and recovery: Show URLs only after the new gate succeeds. Project prerequisites: Resource graphs Idempotency Tenant isolation Engineer value: Practice ephemeral environment lifecycle, scoped configuration, cleanup, quotas, and provider reconciliation. Company value: Review changes in isolated representative environments while controlling leakage, resource growth, and abandoned infrastructure. AI tools are welcome during implementation. Record assumptions, review the result, and verify its behavior. Planning status does not create Outcome Evidence or Ownership Evidence. #### DPREVIEW-107 — Enforce preview quotas across concurrent requests **Story · High priority · Expert** noCV practice brief v5 · DPREVIEW-107 · Create review environments that clean themselves up Fictional engineering practice briefs. Starter repositories, fixtures, automated grading, and verified ownership are not included. Phase: Control change and failure. Depends on: DPREVIEW-103, DPREVIEW-104. Difficulty: Expert. Estimated focused work: 360 minutes; setup and prerequisite tickets are additional. Estimated field mix: DevOps 60% · Distributed systems 40%. Field percentages are editorial estimates of the ticket's engineering focus. They total 100%; they are not measured time, proficiency scores, or ownership evidence. Two valid plans each fit the remaining quota, then apply concurrently and exceed the team limit together. Acceptance criteria - Quota reservation and environment admission are atomic - Expired reservations are reclaimed through identity-checked leases - Provider failure releases or reconciles reservation deterministically Implementation constraints - Do not hold a database transaction open across provider operations. Verification - Admit concurrent plans whose combined cost fits exactly. - Race two plans over the limit and verify only one obtains authority to apply. Deliverables - Quota reservation protocol and concurrency tests Rollout and recovery: Start with conservative team quotas and visible denials. Project prerequisites: Resource graphs Idempotency Tenant isolation Engineer value: Practice ephemeral environment lifecycle, scoped configuration, cleanup, quotas, and provider reconciliation. Company value: Review changes in isolated representative environments while controlling leakage, resource growth, and abandoned infrastructure. AI tools are welcome during implementation. Record assumptions, review the result, and verify its behavior. Planning status does not create Outcome Evidence or Ownership Evidence. ### Operate and improve Measure the workflow, rehearse recovery, and document ownership. #### DPREVIEW-108 — Expire previews without deleting an active replacement **Chore · High priority · Advanced** noCV practice brief v5 · DPREVIEW-108 · Create review environments that clean themselves up Fictional engineering practice briefs. Starter repositories, fixtures, automated grading, and verified ownership are not included. Phase: Operate and improve. Depends on: DPREVIEW-101, DPREVIEW-104. Difficulty: Advanced. Estimated focused work: 240 minutes; setup and prerequisite tickets are additional. Estimated field mix: DevOps 70% · Cloud infrastructure 30%. Field percentages are editorial estimates of the ticket's engineering focus. They total 100%; they are not measured time, proficiency scores, or ownership evidence. A delayed cleanup job for an old preview alias deletes storage now owned by a newer environment. Acceptance criteria - Cleanup binds immutable environment and resource identities - Deletion compares current provider ownership before action - Alias reuse cannot transfer cleanup authority Implementation constraints - Use fake providers and delete only resources returned by the scoped plan. Verification - Expire one environment and remove exactly its resource graph. - Reuse its alias for a new environment before delayed cleanup and confirm new resources survive. Deliverables - Fenced expiry job and alias-reuse regression Rollout and recovery: Run cleanup in report-only mode before enabling deletions. Project prerequisites: Resource graphs Idempotency Tenant isolation Engineer value: Practice ephemeral environment lifecycle, scoped configuration, cleanup, quotas, and provider reconciliation. Company value: Review changes in isolated representative environments while controlling leakage, resource growth, and abandoned infrastructure. AI tools are welcome during implementation. Record assumptions, review the result, and verify its behavior. Planning status does not create Outcome Evidence or Ownership Evidence. #### DPREVIEW-109 — Resume partial preview deletion without losing unresolved resources **Task · High priority · Expert** noCV practice brief v5 · DPREVIEW-109 · Create review environments that clean themselves up Fictional engineering practice briefs. Starter repositories, fixtures, automated grading, and verified ownership are not included. Phase: Operate and improve. Depends on: DPREVIEW-108. Difficulty: Expert. Estimated focused work: 360 minutes; setup and prerequisite tickets are additional. Estimated field mix: DevOps 60% · Site reliability 40%. Field percentages are editorial estimates of the ticket's engineering focus. They total 100%; they are not measured time, proficiency scores, or ownership evidence. DNS deletion succeeds, storage deletion times out after acceptance, and the environment is marked deleted despite an unknown storage outcome. Acceptance criteria - Deletion tracks each resource as pending, deleted, absent, failed, or unknown - Retry reconciles unknown provider state before mutation - Environment closes only when every resource reaches a resolved terminal state Implementation constraints - Unknown does not equal absent; provider responses remain untrusted until identity reconciliation. Verification - Delete a full graph and replay the job idempotently. - Lose a storage-delete response and confirm the environment remains visibly unresolved. Deliverables - Deletion state machine and partial-failure drill Rollout and recovery: Alert on aged unresolved cleanup rather than hiding it. Project prerequisites: Resource graphs Idempotency Tenant isolation Engineer value: Practice ephemeral environment lifecycle, scoped configuration, cleanup, quotas, and provider reconciliation. Company value: Review changes in isolated representative environments while controlling leakage, resource growth, and abandoned infrastructure. AI tools are welcome during implementation. Record assumptions, review the result, and verify its behavior. Planning status does not create Outcome Evidence or Ownership Evidence. #### DPREVIEW-110 — Report preview value and cost without vanity counts **Bug · Medium priority · Intermediate** noCV practice brief v5 · DPREVIEW-110 · Create review environments that clean themselves up Fictional engineering practice briefs. Starter repositories, fixtures, automated grading, and verified ownership are not included. Phase: Operate and improve. Depends on: DPREVIEW-106, DPREVIEW-107, DPREVIEW-109. Difficulty: Intermediate. Estimated focused work: 150 minutes; setup and prerequisite tickets are additional. Estimated field mix: DevOps 70% · Site reliability 30%. Field percentages are editorial estimates of the ticket's engineering focus. They total 100%; they are not measured time, proficiency scores, or ownership evidence. A dashboard celebrates total previews created while ignoring failed readiness, time-to-review, idle duration, and leaked resources. Acceptance criteria - Report creation-to-ready time, ready duration, cleanup latency, failures, and declared resource cost - Metrics use bounded repository and outcome dimensions - Unresolved deletion remains included until reconciled Implementation constraints - Do not infer developer productivity or individual performance from preview usage. Verification - Reconcile a mixed fixture cohort from request through deletion. - Omit cleanup observations and confirm the report shows incomplete cost and lifecycle data. Deliverables - Preview lifecycle report and interpretation guide Rollout and recovery: Use the report to tune lifecycle policy, not rank people. Project prerequisites: Resource graphs Idempotency Tenant isolation Engineer value: Practice ephemeral environment lifecycle, scoped configuration, cleanup, quotas, and provider reconciliation. Company value: Review changes in isolated representative environments while controlling leakage, resource growth, and abandoned infrastructure. AI tools are welcome during implementation. Record assumptions, review the result, and verify its behavior. Planning status does not create Outcome Evidence or Ownership Evidence.