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 PLATENCY-101 Task Foundational
The last benchmark sent one route repeatedly. Dispatch says the slow period contains mostly unique routes and a small number of expensive multi-stop quotes.
Estimated field mix
Performance engineering 70% Quality engineering 30% Find the missing seconds in the quote APIPLATENCY-102 Story Intermediate
The dashboard median improves when the slowest requests time out and disappear from successful-response measurements.
Estimated field mix
Performance engineering 50% Site reliability 30% Privacy engineering 20% Find the missing seconds in the quote APIPLATENCY-103 Task Foundational
A trace labels the entire request as carrier latency, but the stub returns quickly when called outside the API.
Estimated field mix
Performance engineering 60% Site reliability 40% Find the missing seconds in the quote APIPLATENCY-104 Bug Advanced
A CPU profile shows every quote parsing the same tariff document, including requests that use the same immutable tariff revision.
Estimated field mix
Performance engineering 70% Backend 30% Find the missing seconds in the quote APIPLATENCY-105 Bug Advanced
A client disconnects after its deadline, but the carrier lookup continues and consumes one of the few available connections.
Estimated field mix
Performance engineering 40% Networking 30% Backend 30% Find the missing seconds in the quote APIPLATENCY-106 Story Advanced
Multi-stop quotes fan out immediately. A burst exhausts the carrier stub connection pool and slows unrelated single-stop traffic.
Estimated field mix
Performance engineering 50% Backend 30% Site reliability 20% Find the missing seconds in the quote APIPLATENCY-107 Task Intermediate
The largest multi-stop responses correlate with event-loop delay. The team has proposed adding workers before confirming where time is spent.
Estimated field mix
Performance engineering 70% Backend 30% Find the missing seconds in the quote APIPLATENCY-108 Task Expert
At overload, a larger queue increases completed work but most quotes arrive after the dispatch screen has already given up.
Estimated field mix
Performance engineering 60% Site reliability 40% Find the missing seconds in the quote APIPLATENCY-109 Chore Intermediate
A promising result came from a generator sharing the API CPU quota. It slowed its own arrivals and reported a workload the service never received.
Estimated field mix
Performance engineering 70% Quality engineering 30% Find the missing seconds in the quote APIPLATENCY-110 Chore Expert
The team can demonstrate one fast run, but it has no rule for accepting noisy results or reverting a change that prices correctly only at low concurrency.
Estimated field mix
Performance engineering 50% Quality engineering 30% Site reliability 20% Find the missing seconds in the quote APIPQUERY-101 Task Foundational
The existing fixture spreads rows evenly across tenants. It cannot reproduce the large account whose open-work view is slow.
Estimated field mix
Data engineering 50% Quality engineering 30% Performance engineering 20% Keep the operations inbox fast as history growsPQUERY-102 Task Foundational
The ticket says the query takes seconds but contains no plan, parameters or indication of whether the cache was warm.
Estimated field mix
Database engineering 50% Performance engineering 50% Keep the operations inbox fast as history growsPLATENCY / Performance engineering Explain and reduce quote latency under a mixed workload without weakening pricing correctness.
PQUERY / Performance engineering Tune a tenant-scoped PostgreSQL inbox using plans, representative distributions and reversible changes.
PWEB / Performance engineering Investigate browser loading, rendering and interaction costs while preserving usable scheduling workflows.
PBATCH / Performance engineering Make a bounded catalog import stream, recover and report progress under explicit resource limits.
PCACHE / Performance engineering Measure cache value, prevent refill storms and bound staleness without hiding origin failures.
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.