Design, implement, test, and review bounded in-process Go concurrency using goroutines, channels, iterators, mutexes, shared collections, WaitGroup, errgroup, backpressure, ordering, cancellation, and deterministic lifecycle checks.
SkillScore96Maintained
Automatic
◆Coding pack
Last verified 8/16/2026
What it changes
Passed 24 of 25 test cases with the skill, and 23 of 25 without it.
Without skill92%
With skill96%
Checks it passed that the model alone missed
All worker goroutines are joined using synchronization constructs before the pipeline function returns.
1 fixed23 passed either way1 still failing0 broke
Pass-rate lift
+4 pp
Tokens
+9%
Agent turns
0%
Response time
-22%
Model gemini-3.6-flashMeasured 8/16/2026v124 of 25 cases passed with skill
Tokens, turns and time describe resource use, not a dollar price.
See it in action
A test case the skill fixed. Same model, same prompt, with and without the skill.
Prompt
I am building a high-throughput image processing pipeline in Go that takes a stream of file paths, fetches them, applies transformations, and saves them. I need a code review and refactored Go implementation that properly manages concurrent worker routines, bounds system resources, and ensures all background tasks shut down cleanly when a context is cancelled. Please provide the refactored code alongside an architecture overview.
What was checked, without and with the skill
Checked
Without skill
With skill
Worker goroutines select on context cancellation during channel operations.
Passed
Passed
All worker goroutines are joined using synchronization constructs before the pipeline function returns.
Missed
Passed
case-01 · gemini-3.6-flash · 8/16/2026 · answers are capped and redacted
What's inside
The instructions your model reads when the skill loads.
SKILL.md54 linessingle file
Go Concurrency Pipelines
Every goroutine needs an owner, a stop condition, and a completion path. Bound
admission before optimizing throughput.
Core Workflow
Define input, output, ordering, partial-result, and failure contracts.
Prefer a synchronous or iterator API unless callers need channel mechanics.
Assign ownership of goroutines, channel closure, timers, and cancellation.
Bound concurrency, queues, retries, and memory together.
Make every blocking send, receive, and wait cancellation-aware.
Join all owned goroutines on success, failure, cancellation, and early exit.
Test lifecycle behavior with barriers and deadlines rather than sleeps.