Satyam Kesharwani's Engineering Blog https://www.satyamk.dev/blog Write-ups on databases, distributed systems, C++ performance and machine learning by Satyam Kesharwani. en Tue, 06 Oct 2026 00:00:00 GMT Building a Key-Value Database from Scratch in C++: epoll, LRU Cache and B-Tree https://www.satyamk.dev/blog/atomickv-key-value-store-cpp-epoll-btree https://www.satyamk.dev/blog/atomickv-key-value-store-cpp-epoll-btree Tue, 06 Oct 2026 00:00:00 GMT stym4193@gmail.com (Satyam Kesharwani) How one AtomicKV node works: a single-threaded Linux epoll event loop, an O(1) LRU cache behind a Bloom filter, and an on-disk B-Tree in C++17, with benchmarks. C++ Databases Systems Linux Distributing a C++ Key-Value Store: Consistent Hashing, Gossip and Read Repair https://www.satyamk.dev/blog/atomickv-distributed-consistent-hashing-gossip-replication https://www.satyamk.dev/blog/atomickv-distributed-consistent-hashing-gossip-replication Tue, 06 Oct 2026 00:00:00 GMT stym4193@gmail.com (Satyam Kesharwani) AtomicKV as a masterless cluster: consistent hashing with virtual nodes, gossip failure detection, Lamport clocks, replication, read repair and anti-entropy, in C++. Distributed Systems C++ Databases Building a URL Shortener with 7 ms Redirects: LRU, Redis and PostgreSQL Caching https://www.satyamk.dev/blog/url-shortener-system-design-redis-postgresql-caching https://www.satyamk.dev/blog/url-shortener-system-design-redis-postgresql-caching Tue, 06 Oct 2026 00:00:00 GMT stym4193@gmail.com (Satyam Kesharwani) Shortify's design: two cache layers over PostgreSQL, a Redis Bloom filter, cache-stampede locks, Snowflake IDs in Base62 and a token-bucket rate limiter in Node.js. Backend System Design Redis PostgreSQL From Behavior to Pixels: Android Ransomware Detection with a Vision Transformer https://www.satyamk.dev/blog/android-ransomware-detection-vision-transformer https://www.satyamk.dev/blog/android-ransomware-detection-vision-transformer Tue, 06 Oct 2026 00:00:00 GMT stym4193@gmail.com (Satyam Kesharwani) Our ICDAM 2025 paper: sandbox behaviour of 4,280 Android apps turned into features and images, then classified by a Random Forest, CNNs and a ViT (99.78% accuracy). Machine Learning Security Research Physics-Informed TinyML on an ESP32: Estimating Battery SOC and SOH https://www.satyamk.dev/blog/tinyml-esp32-battery-soc-soh-physics-informed-neural-network https://www.satyamk.dev/blog/tinyml-esp32-battery-soc-soh-physics-informed-neural-network Tue, 06 Oct 2026 00:00:00 GMT stym4193@gmail.com (Satyam Kesharwani) An offline ESP32 battery monitor from our IEEE paper: a physics-informed neural network (R² 99.70%) compressed to INT8 with Edge Impulse EON, plus no-start prediction. Machine Learning IoT Embedded Research Building a RAG PDF Assistant with LangChain, FAISS and Gemini https://www.satyamk.dev/blog/rag-pdf-assistant-langchain-faiss-gemini https://www.satyamk.dev/blog/rag-pdf-assistant-langchain-faiss-gemini Tue, 06 Oct 2026 00:00:00 GMT stym4193@gmail.com (Satyam Kesharwani) How Chatur answers questions about PDFs with RAG: PyPDF2 extraction, recursive chunking, Gemini embeddings in FAISS, a grounded prompt, and lessons on chunk size. AI Python RAG Custom Memory Allocators for an Order Matching Engine in C++ https://www.satyamk.dev/blog/building-hft-engine-cpp https://www.satyamk.dev/blog/building-hft-engine-cpp Wed, 22 Jul 2026 00:00:00 GMT stym4193@gmail.com (Satyam Kesharwani) Four C++ memory allocators written from scratch (linear, stack, pool, free list), how a limit order book uses them, and a fair benchmark against glibc new/delete. C++ Systems Memory Allocators