Mathias Paulenko
Software Engineer & Founder of StackPractices
Mathias Paulenko
Software Engineer
Software engineer with 12+ years of experience building production systems across Python, JavaScript, React, and DevOps. I have contributed to enterprise projects spanning CI/CD pipelines, API design, cloud infrastructure, and full-stack development.
StackPractices is my personal project, born from a simple belief: great documentation should be copy-paste ready. Every recipe, pattern, and guide on this site is designed to save you time and help you ship faster.
Published Works (1032)
Safely Extract Zip Files with Python
How to extract and validate zip archives securely using Python zipfile and shutil.
Human-in-the-Loop Pattern
Pause LLM agent execution for human approval before high-impact actions. Route decisions to a...
Twin Pattern
Link two classes through mutual references so they delegate methods to each other: a...
Islands Architecture: Partial Hydration for Faster Pages
Server-render the page as static HTML and hydrate only the interactive islands. Covers Astro client...
Circuit Breaker Half-Open
How to test service recovery with half-open circuit breaker state transitions. Covers closed, open,...
Failover: Switch to Standby on Primary Failure Detection
How to move traffic to a standby system when the primary fails. Covers active-passive,...
API Deprecation Notice Template
A template for communicating API deprecations, breaking changes, and sunset timelines to consumers.
CI/CD Pipeline Security Template
A template for securing build and deployment pipelines against credential leaks, tampering, supply...
On-Call Runbook Template
A template documenting common alerts and step-by-step response procedures for on-call engineers.
Frontend Performance Budget Template
A template for defining JS, CSS, image, and font budgets per route — with a method for picking the...
Cache Invalidation Pattern
Strategies for keeping cached data fresh: TTL expiration, explicit invalidation, write-through, and...
Write-Behind Cache Pattern
Write to the cache synchronously and persist to the database asynchronously for high-throughput...
AI LLM Incident Response Runbook
Operational runbook for LLM production incidents: hallucination events, model outages, cost spikes,...
Data Migration Runbook Template with Rollback Steps
Use this data migration runbook template to plan safe migrations. Includes pre-migration checks,...
Weekly Ops Review Template
A template for summarizing incidents, costs, performance, and action items in weekly operations...
Serverless Cost Estimation Template
Template for estimating serverless costs per workload: invocation pricing, GB-second math, data...
Cloud Cost Optimization Guide
A practical guide to cloud cost optimization: right-sizing, reserved instances, spot instances,...
Apply Prompt Engineering: What Works
How to write useful prompts for LLMs using role assignment, few-shot examples, chain-of-thought...
AssertJ Soft Assertions in JUnit5: Collect All Failures
How to use AssertJ soft assertions in JUnit5 to collect multiple assertion failures in a single...
Compute Resource Consolidation Pattern
Combine workloads into fewer compute resources to reduce cost, improve utilization, and simplify...
Blackboard Pattern
A shared knowledge space where independent specialized modules collaborate to solve complex...
CSS Architecture: Utility-First with Component-Scoped Layers
How to organize CSS with utility-first classes and component-scoped layers. Covers Tailwind CSS,...
Scheduler Agent Supervisor Pattern
Coordinate resilient job scheduling with a supervisor that monitors agents, restarts failures, and...
API Lifecycle Management Template
A copy-paste checklist template for managing API deprecation, versioning transitions, and safe...