--- title: "Kaustav Sarkar (@kaustavsarkar) | Hashnode" description: "SDE Cloudera. Read the latest articles by Kaustav Sarkar on Hashnode." url: "https://hashnode.com/@kaustavsarkar" --- @kaustavsarkar # Kaustav Sarkar @kaustavsarkar · Bengaluru · Joined May 2026 SDE Cloudera [Website](https://kaustavsarkar.dev/) ### [Patterns, Anti-Patterns, and Operational Reality](https://blogs.kaustavsarkar.dev/istio-mesh-patterns?utm_source=hashnode&utm_medium=feed) How the mesh keeps identity, authorization, and data controls separate in practice 13 min read · [blogs.kaustavsarkar.dev](https://blogs.kaustavsarkar.dev/istio-mesh-patterns?utm_source=hashnode&utm_medium=feed) [Sep 1](https://hashnode.com/posts/istio-mesh-patterns/6a970b6fb9508e501cbf8cca) ### [Layered Authorization: Network to Database](https://blogs.kaustavsarkar.dev/layered-authorization-network-to-database?utm_source=hashnode&utm_medium=feed) How network, request, resource, and field checks compose, with Postgres row-level security as the backstop 12 min read · [blogs.kaustavsarkar.dev](https://blogs.kaustavsarkar.dev/layered-authorization-network-to-database?utm_source=hashnode&utm_medium=feed) [Sep 1](https://hashnode.com/posts/layered-authorization-network-to-database/6a96b1b6d94ae3f6886c1f0b) ### [Signing Mesh Tokens with Vault](https://blogs.kaustavsarkar.dev/vault-transit-signing?utm_source=hashnode&utm_medium=feed) Why the private signing key stays in Vault, how rotation avoids 403s, and the blast radius when a component is compromised 13 min read · [blogs.kaustavsarkar.dev](https://blogs.kaustavsarkar.dev/vault-transit-signing?utm_source=hashnode&utm_medium=feed) [Jul 9](https://hashnode.com/posts/vault-transit-signing/6a4f6daec69db835216e1d31) ### [The Identity Flow: From Gateway to Database](https://blogs.kaustavsarkar.dev/identity-flow-gateway-to-database?utm_source=hashnode&utm_medium=feed) Tracing one request through eight checkpoints, from an Envoy header strip at the gateway to Postgres row-level security 15 min read · [blogs.kaustavsarkar.dev](https://blogs.kaustavsarkar.dev/identity-flow-gateway-to-database?utm_source=hashnode&utm_medium=feed) [2](https://hashnode.com/posts/identity-flow-gateway-to-database/6a4bc269feaaeb7f1f5820cf) [Jul 6](https://hashnode.com/posts/identity-flow-gateway-to-database/6a4bc269feaaeb7f1f5820cf) ### [Service Mesh Zero-Trust Architecture](https://blogs.kaustavsarkar.dev/anatomy-of-zero-trust-service-mesh?utm_source=hashnode&utm_medium=feed) A practical guide to building zero-trust applications on Istio 14 min read · [blogs.kaustavsarkar.dev](https://blogs.kaustavsarkar.dev/anatomy-of-zero-trust-service-mesh?utm_source=hashnode&utm_medium=feed) [Jun 9](https://hashnode.com/posts/anatomy-of-zero-trust-service-mesh/6a2872217015b40bd2559cec)