# Sahil's Playbook

> Sahil Kapoor is the founder of CarInfo (70M downloads, acquired by Cars24) and former technical architect of ixigo Trains (30M MAU). He writes about distributed systems, AI infrastructure, product thinking, and what engineering leadership looks like at scale.

## Engineering

- [Synchronized Expiration in Distributed Systems](https://sahilkapoor.com/synchronized-expiration-in-distributed-systems/): How deterministic TTLs in caching systems create hidden synchronization failures under scale, and how mature systems design around them.
- [Redis as Infrastructure: Caching, Coordination, and Scale](https://sahilkapoor.com/redis-in-modern-systems/): A practical guide to using Redis as a coordination layer across distributed systems, not just a cache.
- [Batch Processing in Modern Systems](https://sahilkapoor.com/batch-processing-in-modern-systems/): Why batching is a systems tax you cannot avoid, and how to design around it in distributed architectures.
- [Software Is Not Flexible. It Hardens as It Grows](https://sahilkapoor.com/software-is-not-flexible/): The engineering reality most teams learn too late: software accumulates constraints faster than it sheds them.
- [MongoDB Data Modeling: How to Design Schemas for Real-World Applications](https://sahilkapoor.com/mongodb-data-modeling/): Document schema design from first principles, modeling data around access patterns rather than convenience.

## AI

- [What is NVIDIA DGX Spark (and why I bought one)](https://sahilkapoor.com/what-is-nvidia-dgx-spark/): First-hand account of running a personal AI supercomputer with 128GB unified memory for local inference.
- [Token Economics: What Every Developer Needs to Understand Now](https://sahilkapoor.com/ai-token-economics-is-changing/): How the shift from subscriptions to token-based AI pricing changes what you build and how you architect it.
- [2026 Prediction: Foundation Models Are Becoming a Black Hole for AI Startups](https://sahilkapoor.com/2026-prediction-foundation-models-are-becoming-a-black-hole-for-ai-startups/): Why foundation model providers are becoming gravity wells that pull entire product categories inward.
- [How Cybersecurity Will Evolve in 2026](https://sahilkapoor.com/how-cybersecurity-will-evolve-in-2026/): What the security landscape looks like when AI is on both sides of the attack surface.

## Product

- [Why You Should Not Build for 10 Million Users on Day One](https://sahilkapoor.com/why-you-should-not-build-for-10-million-users-on-day-one/): The case against premature architectural ambition, and what over-engineered early systems actually cost.
- [Best AI Tools for Product Managers in 2026](https://sahilkapoor.com/best-ai-tools-for-product-managers/): A practical breakdown of AI tools for PMs covering prototyping, research, documentation, and roadmapping.

## Leadership

- [Make the Consequence Real](https://sahilkapoor.com/make-the-consequence-real/): Why clarity, dashboards, and alignment are not enough at engineering leadership scale, and what actually moves teams.
- [Your Career Isn't a Ladder, It's a Metamorphosis](https://sahilkapoor.com/career-is-a-metamorphosis/): Careers as cycles of curiosity, chaos, and transformation rather than linear progression.
- [Beyond Paycheques: What Truly Keeps Employees Engaged](https://sahilkapoor.com/what-truly-keeps-employees-engaged/): A candid look at retention covering recognition, growth, flexibility, and genuine human connection.

## Engineering Glossary

- [Engineering Glossary](https://sahilkapoor.com/engineering-glossary/): 169 engineering terms covering AI tooling (LLMs, RAG, MCP, LoRA, vLLM), infrastructure (Helm, ArgoCD, Pulumi, Tailscale, WireGuard), frontend frameworks (React, Next.js, Vue, Svelte), and databases (Redis, MongoDB, pgvector). Each entry is 200 to 400 words with real context, not just a definition.

## About

- [/uses](https://sahilkapoor.com/uses/): The hardware, software, and AI stack Sahil uses daily, including a personal AI supercomputer, local LLM setup via Ollama and Tailscale, and Claude Code as a daily driver.
- [FAQ](https://sahilkapoor.com/faq/): Background, how to get in touch, and how the blog works.
- Site: https://sahilkapoor.com
- Author: https://sahilkapoor.com/author/sahil/