Engineering task library · Version 5 Work that feels like work. Design a system. Diagnose tail latency. Ship a migration. Recover a failed rollout. Pick a focused ticket or follow a project through its delivery phases.
1380 tickets · 138 projects · 26 engineering fields · Four difficulty levels
Practice briefs Fictional engineering practice briefs. Starter repositories, fixtures, automated grading, and verified ownership are not included. Completing a ticket does not issue a credential.
AI tools are welcome during implementation. Record assumptions, review the result, and verify its behavior.
Field percentages are editorial estimates of the ticket's engineering focus. They total 100%; they are not measured time, proficiency scores, or ownership evidence.
Pattern topics identify design choices to practice. Read the ticket's acceptance criteria and justify the simplest suitable approach. Tags are not capability or ownership evidence; an untagged ticket has no curated pattern topic assigned.
Field counts and the engineering field filter use each project's primary field. Estimated ticket labels can span multiple fields.
Backend 60 Data engineering 50 Platform engineering 50 Security 50 Frontend 60 Mobile 50 Developer tooling 50 Quality engineering 50 Applied AI 50 Integrations 60 Real-time systems 50 Accessibility 50 System design 60 Performance engineering 50 Database engineering 50 Distributed systems 60 Site reliability 50 Cloud infrastructure 50 Networking 50 API design 50 Storage systems 50 Compiler and language tooling 60 Embedded and edge 50 Privacy engineering 50 Systems programming 60 DevOps 60 PQUERY-107 Bug Expert
The same prepared inbox statement serves tiny tenants and the dominant tenant. A plan that works for one distribution performs poorly for the other.
Estimated field mix
Database engineering 60% Performance engineering 40% Keep the operations inbox fast as history growsPQUERY-108 Chore Advanced
The proposed index works after a clean restore. Nobody has checked what happens when creation is interrupted while the application is updating work orders.
Estimated field mix
Database engineering 60% Site reliability 30% Performance engineering 10% Keep the operations inbox fast as history growsPQUERY-109 Chore Intermediate
A new nullable column changed the seed loader. The benchmark still completes, but most rows now take a cheap fallback path that users rarely see.
Estimated field mix
Quality engineering 50% Data engineering 30% Performance engineering 20% Keep the operations inbox fast as history growsPQUERY-110 Task Expert
The review has several attractive charts but no single explanation of which changes should ship together or what would trigger rollback.
Estimated field mix
Performance engineering 50% Database engineering 50% Keep the operations inbox fast as history growsPWEB-101 Task Foundational
The issue report says the screen feels slow. Developers reproduce it with different data and disagree about which interaction is responsible.
Estimated field mix
Performance engineering 50% Quality engineering 30% Frontend 20% Make a large scheduling screen respond to the next clickPWEB-102 Task Foundational
The screen downloads export and map code before the user opens either feature. The team needs sizes and dependency paths before splitting bundles.
Estimated field mix
Performance engineering 60% Frontend 40% Make a large scheduling screen respond to the next clickPWEB-103 Story Intermediate
A render counter improved after memoization, but typing still stalls because sorting and formatting happen before React commits.
Estimated field mix
Performance engineering 60% Frontend 40% Make a large scheduling screen respond to the next clickPWEB-104 Story Intermediate
The spreadsheet export dependency adds work to every schedule visit even though the baseline user never exports.
Estimated field mix
Frontend 50% Performance engineering 30% Accessibility 20% Make a large scheduling screen respond to the next clickPWEB-105 Story Advanced
Every filter mounts hundreds of offscreen job rows. A first virtualization attempt is faster but drops focus when the selected row scrolls away.
Estimated field mix
Performance engineering 40% Frontend 30% Accessibility 30% Make a large scheduling screen respond to the next clickPWEB-106 Bug Advanced
Date and duration formatting dominates repeated filters. A broad memoization patch reuses labels after the schedule time zone changes.
Estimated field mix
Performance engineering 60% Frontend 40% Make a large scheduling screen respond to the next clickPWEB-107 Story Expert
Fast typing schedules several expensive filter computations. Results from an earlier query briefly replace the latest selection and consume time after they are irrelevant.
Estimated field mix
Performance engineering 50% Frontend 50% Make a large scheduling screen respond to the next clickPWEB-108 Bug Advanced
The screen starts responsive and degrades after operators open and close it throughout a shift. Detached rows remain reachable through subscriptions.
Estimated field mix
Performance engineering 60% Frontend 40% Make a large scheduling screen respond to the next clickA11Y / Accessibility Repair public-service booking across keyboard use, zoom, timeouts, and changing availability.
READ / Accessibility Improve navigation, text adaptation, annotations, and revision recovery in an internal document reader.
LIVE / Real-time systems Build a bounded live coordination room with ordered events, reconnect recovery, and clear authority.
FLEET / Real-time systems Reconcile synthetic vehicle locations, assignment changes, and stream interruptions in an operations dashboard.
CLI / Developer tooling Build a local release assistant that prepares reviewable plans and survives interrupted release steps.
BUILD / Developer tooling Shorten a local monorepo check loop while retaining correctness when inputs, dependencies, or tools change.
CHECK / Quality engineering Build a deterministic checkout regression suite around pricing, accessibility, payment failures, and isolated test data.
REPLAY / Quality engineering Create a local webhook laboratory that reproduces duplicates, disorder, signature failures, and interrupted delivery.
SEARCH / Applied AI Build a retrieval workflow that respects document access, cites exact revisions, and declines unsupported answers.
TRIAGE / Applied AI Build a routing assistant that suggests queues, validates model output, and preserves accountable human corrections.
SYNC / Integrations Build a vendor inventory connector with stable identity mapping, resumable ingestion, reconciliation, and tenant-safe operations.
CAL / Integrations Build a calendar booking workflow with time-zone rules, conflict handling, idempotent provider calls, and safe reconnect behavior.
Take the brief into your own workflow. For engineers Practice scoped changes, keep a portable implementation and verification record, and learn to explain operational tradeoffs. Choose a ticket whose prerequisites you can provide.
For companies Use realistic work to structure onboarding, internal practice, and conversations about engineering decisions. Each project names the delivery benefit. Agree scope and compensation before requesting company-specific work.
CSV contains one row per ticket. Map fields and issue types in your tracker; project grouping and dependency keys are descriptive. JSON preserves the complete project structure. These downloads do not synchronize with Jira.