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)
Read and Write Files
How to read from and write to files safely across multiple programming languages.
Process Large Files with Streams
How to read, transform, and write large files efficiently using streams without loading entire files into memory in Python, Node.js, and...
Implement Lazy Loading for Images, Components, and Data
How to defer loading of non-critical resources until they are needed, improving initial page load time, reducing bandwidth, and optimizing...
Secure APIs with HTTP Security Headers
How to configure essential security headers like HSTS, CSP, and X-Frame-Options to protect APIs and web applications from common attacks.
Protect Web Forms Against CSRF Attacks
How to prevent Cross-Site Request Forgery attacks using synchronizer tokens, SameSite cookies, and double-submit cookie patterns.
Implement Rate Limiting for APIs and Web Applications
How to protect APIs and web endpoints from abuse using token bucket, sliding window, and fixed window rate limiting strategies with Redis...
Prevent SQL Injection Attacks
How to write parameterized queries and use ORMs to eliminate SQL injection vulnerabilities across Python, JavaScript, and Java.
Prevent Cross-Site Scripting (XSS)
How to sanitize user input, escape output, and use Content Security Policy to prevent XSS attacks in web applications.
Build Event-Driven Serverless Architectures
How to design loosely coupled systems using serverless functions triggered by events from message queues, databases, and webhooks.
Build Real-Time APIs with WebSockets on Serverless
How to implement bidirectional real-time communication using WebSockets with AWS API Gateway, Lambda, DynamoDB, and what works in...
Run Scheduled Jobs with Serverless Functions
How to replace cron jobs with serverless scheduled functions for backups, reporting, cleanup, and periodic maintenance tasks.
Build Serverless APIs with API Gateway
How to design, deploy, and manage serverless HTTP APIs using AWS API Gateway, Lambda, and function-as-a-service patterns.
Test API Contracts with Consumer-Driven Contracts
How to prevent breaking changes between microservices using consumer-driven contract testing with Pact and OpenAPI validators.
Write Integration Tests
How to test multiple components working together using real databases, HTTP clients, and message queues in Python, JavaScript, and Java.
Write Unit Tests with Mocks and Stubs
How to isolate code under test using mock objects, stubs, and spies to replace external dependencies like databases, APIs, and file systems.
Fine-Tune a Language Model for Code Generation
How to fine-tune a large language model for domain-specific code generation using LoRA, QLoRA, and custom datasets
Build a RAG Pipeline with LangChain and Vector Databases
How to build a Retrieval-Augmented Generation (RAG) pipeline using LangChain and vector databases for AI-powered search
Implement Semantic Search with Embeddings
How to implement semantic search using text embeddings and vector similarity search for intelligent document retrieval
Implement API Logging and Audit Trails
Set up thorough request/response logging and audit trails for APIs with structured output, correlation IDs, and compliance considerations.
Implement a GraphQL API
Build a production-ready GraphQL API with type-safe schemas, resolvers, and query optimization in Python, JavaScript, and Java.
Build Real-Time Notifications with WebSockets
Implement a real-time notification system using WebSockets and Redis pub/sub for broadcasting messages across clients.
Handle Database Deadlocks and Retries
Detect, prevent, and recover from database deadlocks with automatic retry logic, isolation levels, and query ordering strategies.
Set Up Database Read Replicas for Scaling
Scale read-heavy workloads with database read replicas, replication lag monitoring, and read/write splitting across primary and replica...
Implement Event Sourcing in a Relational Database
Build event sourcing systems using relational databases with event stores, projections, and snapshotting for audit and temporal querying.