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)
Serverless Function Composition Pattern
Chain serverless functions via Step Functions or orchestration layers to build multi-step workflows...
Serverless Throttling Pattern
Handle backpressure in serverless by using SQS, token buckets, and concurrency limits to protect...
Serverless Warm Pool Pattern
Keep Lambda functions warm by sending periodic ping events to reduce cold start latency for...
Shed Load Pattern
Drop requests proactively under extreme load to protect the system. Reject excess traffic before it...
Two-Level Cache Pattern
Combine an L1 in-memory cache with an L2 distributed cache to reduce latency for hot keys while...
Write-Through Cache Pattern
Synchronously write to both cache and backing store so the cache always has the latest data without...
GraphQL Batched Resolver Pattern
Resolve nested GraphQL fields in a single batched request to eliminate N+1 queries and reduce...
GraphQL Connection Pagination Pattern
Implement Relay-style cursor-based pagination with edges, nodes, and pageInfo for stable GraphQL...
GraphQL DataLoader Pattern
Coalesce individual load requests into batched calls with per-request caching to prevent N+1...
GraphQL Error Extension Pattern
Attach structured metadata to GraphQL errors using extension codes for predictable client-side...
GraphQL Interface Polymorphism Pattern
Model polymorphic types with GraphQL interfaces to share field contracts across different object...
GraphQL Schema Stitching Pattern
Merge multiple independent GraphQL schemas into a single unified schema that clients can query as...
Build Stateful AI Agents with LangGraph State Machines
Create multi-step AI agents with LangGraph using state machines, conditional edges, tool calling,...
Fine-Tune and Deploy Text Classifiers with Hugging Face
Fine-tune a pre-trained transformer model for text classification using Hugging Face Trainer,...
Compose LCEL Chains in LangChain for Multi-Step LLM
Build composable LLM pipelines with LangChain Expression Language (LCEL) using pipes, parallel...
Evaluate RAG Quality with RAGAS Metrics
Measure RAG pipeline quality using RAGAS framework metrics — faithfulness, answer relevancy,...
Stream LLM Output with Server-Sent Events (SSE)
Stream LLM responses to clients in real-time using Server-Sent Events with FastAPI, OpenAI...
Run LLMs Locally with Ollama for Private Inference
Install and use Ollama to run open-source LLMs locally with Python, including streaming,...
Compare Text Semantic Similarity with OpenAI Embeddings
Generate text embeddings with OpenAI and compute cosine similarity to measure semantic similarity...
Structured JSON Output from OpenAI Function Calling
Use OpenAI function calling and structured outputs to get reliable JSON from LLMs with Pydantic...
a Local RAG Pipeline with ChromaDB and Sentence Transformers
Implement retrieval-augmented generation locally with ChromaDB, sentence-transformers embeddings,...
Store and Query Embeddings in Pinecone Vector Database
Use Pinecone to store, query, and filter vector embeddings for semantic search with metadata...
JavaScript Fetch Retry Logic with Exponential Backoff
Retry failed HTTP requests in JavaScript with exponential backoff
Node.js WebSocket Real-Time Communication with Socket.io
Build real-time WebSocket applications in Node.js with Socket.io