Skills cold-start-optimizer
📦

cold-start-optimizer

v1.0.0 Content revision r1 Safe ⚙️ External commands

Optimize Rust Lambda Cold Starts

Rust Lambda functions can suffer slow first responses when binaries are large or initialization is heavy. This skill guides Claude, Codex, and Claude Code through concrete optimizations for build settings, dependencies, and deployment.

Supports: Claude Codex Code(CC)
🥈 80 Silver

Install with my Agent

Copy this request to your Agent. It includes the canonical Skill page and manifest.

Agent request
Review the Skillstore skill "cold-start-optimizer" from https://skillstore.io/skills/emillindfors-cold-start-optimizer.md and its manifest at https://skillstore.io/api/skills/emillindfors-cold-start-optimizer/manifest. Verify the artifact. You may proceed after verification, subject to the environment's own policy.

Your Agent should still show its plan and request any confirmation required by the security policy.

Agent-readable resources

Use these links when an AI agent, crawler, or script needs clean context instead of reading the full page.

Markdown detail GET /skills/emillindfors-cold-start-optimizer.md Signed manifest GET /api/skills/emillindfors-cold-start-optimizer/manifest Signed lockfile GET /api/skills/emillindfors-cold-start-optimizer/lockfile

Test it

Using "cold-start-optimizer". A Rust Lambda function has a large binary and slow first request time.

Expected outcome:

Recommended actions: reduce release binary size, trim dependency features, defer expensive clients, and measure init duration before deployment.

Using "cold-start-optimizer". A team wants lower latency but must control monthly Lambda cost.

Expected outcome:

Suggested plan: test ARM64 first, optimize initialization next, and reserve provisioned concurrency for strict latency paths.

Using "cold-start-optimizer". A handler initializes SDK clients before the Lambda runtime starts.

Expected outcome:

Review result: move client creation behind lazy access, keep startup minimal, and verify the change with cold start metrics.

Security Audit

Safe
v4 • 7/6/2026 Open versioned report

All static findings are false positives caused by Markdown triple backtick fences and example snippets in SKILL.md. The skill provides Rust AWS Lambda optimization guidance and restricts tools to Read and Grep. No prompt injection, data exfiltration, or executable automation was found.

1
Files scanned
214
Lines analyzed
0
Review items
0
False positives ignored

Risk Factors

⚙️ External commands (23)
SKILL.md:25-32 SKILL.md:32-39 SKILL.md:39-53 SKILL.md:53-56 SKILL.md:56-80 SKILL.md:80-85 SKILL.md:85-88 SKILL.md:88-91 SKILL.md:91-101 SKILL.md:101-106 SKILL.md:106-108 SKILL.md:108-111 SKILL.md:111-113 SKILL.md:113-124 SKILL.md:124-133 SKILL.md:133-141 SKILL.md:141-156 SKILL.md:156-160 SKILL.md:160-172 SKILL.md:172-178 SKILL.md:178-181 SKILL.md:181-185 SKILL.md:185-192
No confirmed security findings were detected by the latest completed static and semantic audit. This does not prove the skill has no side effects.
Audited by: codex View Audit History →
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Security Assessment

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Academic citations (APA · BibTeX · CFF)

APA citation

EmilLindfors. (2026). cold-start-optimizer security audit report (audit version 4) [Author version 1.0.0]. Skillstore. https://skillstore.io/skills/emillindfors-cold-start-optimizer/audits/4

BibTeX citation

@techreport{emillindfors-emillindfors-cold-start-optimizer-2026, author = {EmilLindfors}, title = {cold-start-optimizer security audit report (audit version 4)}, institution = {Skillstore}, year = {2026}, number = {4}, url = {https://skillstore.io/skills/emillindfors-cold-start-optimizer/audits/4}, note = {Author version 1.0.0} }

CITATION.cff

cff-version: 1.2.0 message: "If you use this Skill, cite its author and this versioned security audit report." title: "cold-start-optimizer security audit report (audit version 4)" version: "1.0.0" type: report authors: - name: "EmilLindfors" date-released: "2026-07-06" url: "https://skillstore.io/skills/emillindfors-cold-start-optimizer/audits/4" identifiers: - type: other value: "skillstore:emillindfors-cold-start-optimizer:audit:4" description: "Skillstore immutable audit report identifier"

Skillstore Score

Why this score Evidence Confidence: High
55
Architecture
100
Maintainability
87
Content
69
Community
83
Spec Compliance

What You Can Build

Tune a Rust Lambda Release Build

Review Cargo settings and dependency choices before packaging a Rust function for production Lambda deployment.

Reduce First Request Latency

Identify eager initialization work and move expensive clients behind lazy creation patterns.

Plan Cost-Aware Cold Start Mitigation

Compare ARM64, provisioned concurrency, binary size, and dependency changes for an operational service.

Try These Prompts

Check Build Settings 
Review my Rust Lambda build settings for cold start risk. Suggest safe release profile changes and explain the expected impact.
Find Eager Initialization 
Find eager initialization in this Rust Lambda handler. Recommend lazy alternatives using OnceLock or request-time initialization.
Prioritize Deployment Options 
Compare ARM64, provisioned concurrency, and dependency reductions for this Rust Lambda service. Prioritize changes by latency impact and cost.
Design a Measurement Plan 
Create a cold start measurement plan for production. Include CloudWatch metrics, local checks, and rollout criteria.

Best Practices

  • Measure baseline cold starts before changing build or deployment settings.
  • Keep main initialization minimal and move expensive clients behind lazy creation.
  • Review binary size, dependencies, architecture, and concurrency as one optimization set.

Avoid

  • Treating provisioned concurrency as a replacement for binary and initialization work.
  • Adding broad dependency features without measuring the binary size impact.
  • Deploying command examples unchanged in production environments.

Frequently Asked Questions

What runtimes does this skill focus on?
It focuses on Rust functions deployed to AWS Lambda.
Can it measure my real cold start latency?
No. It provides measurement guidance, but the user must run benchmarks and review CloudWatch metrics.
Does it change AWS resources automatically?
No. The skill provides guidance and examples, and declares only Read and Grep tool access.
When should provisioned concurrency be used?
Use it for strict latency paths after reviewing cost and simpler optimization options.
Why does binary size matter?
Smaller binaries usually load faster and can reduce first request latency.
Can Claude Code or Codex use this with existing projects?
Yes. They can apply the guidance while reviewing project files and deployment settings.

Developer Details

License

MIT

Author version

v1.0.0

Skillstore revision

r1

Repository

https://github.com/EmilLindfors/claude-marketplace/tree/main/plugins/rust-lambda/skills/cold-start-optimizer

Ref

a06681402992ceae98ba04d54cfd4ab004862696

Maintenance freshness

7/18/2026

Usage

4 downloads · 162 views

File structure

📄 SKILL.md