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 (1008)
Implement Graceful Shutdown and Zero-Downtime Restarts
How to implement graceful shutdown and zero-downtime restarts for web servers, workers, and...
Setup SSL Certificates with Let's Encrypt
Step-by-step guide to getting free TLS certificates from Let's Encrypt with Certbot — Nginx,...
JavaScript Event Loop
Understand how the JavaScript event loop works internally and how to write non-blocking code.
Sanitize User Input
How to sanitize and validate user input in Python, Java, and JavaScript to prevent injection...
Implement Event Sourcing in Serverless Architectures
How to capture all changes as immutable events using event sourcing with AWS Lambda, DynamoDB...
Command Pattern with Undo/Redo in TypeScript
Implement the Command pattern to encapsulate requests as objects, enabling undo/redo operations,...
Memento Pattern for State Snapshot and Restoration
Capture and externalize an object's internal state without violating encapsulation, enabling undo,...
Structured Logging: Emit JSON Logs with Consistent Fields
How to emit structured JSON logs with consistent fields for searchability. Covers Python structlog,...
Graceful Shutdown: Drain In-Flight Requests Before Exit
How to drain in-flight requests before process exit. Covers signal handling, health check removal,...
AI Agent Design Document Template (Free Template)
Document AI agent architecture, tools, memory, reasoning patterns, safety guardrails, evaluation...
Production Readiness Review Template
A thorough checklist for verifying that a service, feature, or system is ready for production...
Complete Guide to GitOps in Production
Set up GitOps with ArgoCD or Flux in production: pull-based reconciliation, multi-cluster...
Handle CORS in Express, Flask and Spring Boot
How to configure Cross-Origin Resource Sharing (CORS) headers correctly for APIs, SPAs, and...
Design Event-Driven Systems with Event Buses and Brokers
How to design loosely coupled services with events, event buses, and message brokers — pub/sub...
Implement Secure Session Management
How to create, validate, and expire user sessions securely using HTTP-only cookies, server-side...
Concurrent HTTP Requests with asyncio.gather and aiohttp
Fetch multiple HTTP endpoints concurrently using asyncio.gather and aiohttp with error handling,...
Convert JSON to CSV
How to convert JSON data to CSV format in Python, Java, and JavaScript — flatten nested objects,...
Parse PDF Files in Python, JavaScript and Java
Extract text, tables and metadata from PDF files with Python, JavaScript and Java, including...
ORM CRUD with SQLAlchemy, Prisma & Hibernate
How to run create, read, update, and delete operations with SQLAlchemy, Prisma, and Hibernate — the...
JavaScript Clipboard Copy and Paste
Copy and paste text, HTML, and images in JavaScript with the Clipboard API — secure-context rules,...
Ambassador: Offload Cross-Cutting Concerns to a Proxy
Offload cross-cutting concerns to an ambassador proxy between your clients and external services:...
Message Queue Load Leveling Pattern
Smooth traffic spikes by placing a queue between a producer and a consumer. The producer writes at...
Database Failover Runbook
A step-by-step runbook for executing database failover procedures safely with minimal downtime and...
Monolith to Microservices — Migration Strategies
A practical guide to decomposing monoliths: strangler fig, branch by abstraction, and incremental...