--- title: "Serhii Kalyna (@kalyna-pro) | Hashnode" description: "AI-Driven Developer. Read the latest articles by Serhii Kalyna on Hashnode." url: "https://hashnode.com/@kalyna-pro" --- @kalyna-pro # Serhii Kalyna @kalyna-pro · Joined April 2026 AI-Driven Developer ### [How to Configure Cloudflare for WordPress: Caching & Security Headers](https://kalyna-pro.hashnode.dev/how-to-configure-cloudflare-for-wordpress-caching-038-security-headers?utm_source=hashnode&utm_medium=feed) If you run a WordPress blog, Cloudflare is one of the highest-leverage free tools you can add. It sits between your visitors and your server, caches pages so your origin never gets hammered, and lets you add security headers in seconds — no plugin re... 6 min read · [kalyna-pro.hashnode.dev](https://kalyna-pro.hashnode.dev/how-to-configure-cloudflare-for-wordpress-caching-038-security-headers?utm_source=hashnode&utm_medium=feed) [May 8](https://hashnode.com/posts/how-to-configure-cloudflare-for-wordpress-caching-038-security-headers/69fdc86c882206027ccd7e7b) ### [Prompt Engineering Guide for Developers: Best Practices & Techniques (2026)](https://kalyna-pro.hashnode.dev/prompt-engineering-guide-for-developers-best-practices-038-techniques-2026?utm_source=hashnode&utm_medium=feed) Prompt engineering is the practice of designing inputs that get the best output from an LLM. For developers building on the Claude API, it’s less about “magic phrases” and more about clear communication with a reasoning system. This guide covers the ... 12 min read · [kalyna-pro.hashnode.dev](https://kalyna-pro.hashnode.dev/prompt-engineering-guide-for-developers-best-practices-038-techniques-2026?utm_source=hashnode&utm_medium=feed) [May 8](https://hashnode.com/posts/prompt-engineering-guide-for-developers-best-practices-038-techniques-2026/69fdc86bc9f9029ae3351cbb) ### [Vector Databases Comparison: Pinecone vs Chroma vs Weaviate (2026)](https://kalyna-pro.hashnode.dev/vector-databases-comparison-pinecone-vs-chroma-vs-weaviate-2026?utm_source=hashnode&utm_medium=feed) Choosing a vector database is one of the first decisions in any RAG project. Three options dominate developer usage: Pinecone, Chroma, and Weaviate. Here's a practical comparison. Quick Overview PineconeChromaWeaviate HostingManaged cloud onl... 3 min read · [kalyna-pro.hashnode.dev](https://kalyna-pro.hashnode.dev/vector-databases-comparison-pinecone-vs-chroma-vs-weaviate-2026?utm_source=hashnode&utm_medium=feed) [May 8](https://hashnode.com/posts/vector-databases-comparison-pinecone-vs-chroma-vs-weaviate-2026/69fdb94b97f62678d83a357c) ### [Building a Telegram Bot with Claude API (Python, 2026)](https://kalyna-pro.hashnode.dev/building-a-telegram-bot-with-claude-api-python-2026?utm_source=hashnode&utm_medium=feed) A Telegram bot powered by Claude gives you a personal AI assistant accessible from your phone. In this tutorial you'll build one from scratch — handling messages, keeping conversation history, and deploying it. Prerequisites Python 3.10+ Anthropic ... 3 min read · [kalyna-pro.hashnode.dev](https://kalyna-pro.hashnode.dev/building-a-telegram-bot-with-claude-api-python-2026?utm_source=hashnode&utm_medium=feed) [May 8](https://hashnode.com/posts/building-a-telegram-bot-with-claude-api-python-2026/69fdb80ba96912108f67bdba) ### [RAG vs Fine-Tuning: When to Use Which (Developer's Guide)](https://kalyna-pro.hashnode.dev/rag-vs-fine-tuning-when-to-use-which-developers-guide?utm_source=hashnode&utm_medium=feed) If you're building an LLM-powered application, you'll hit this question quickly: should I use RAG (Retrieval-Augmented Generation) or fine-tune the model? Both approaches customize LLM behavior — but they solve different problems. What Is RAG? RAG r... 3 min read · [kalyna-pro.hashnode.dev](https://kalyna-pro.hashnode.dev/rag-vs-fine-tuning-when-to-use-which-developers-guide?utm_source=hashnode&utm_medium=feed) [May 8](https://hashnode.com/posts/rag-vs-fine-tuning-when-to-use-which-developers-guide/69fdb6c931c160ef94e868ed)