https://anishfyi.com/writings/ Essays on backend systems, applied AI, and the open source tools behind them. en anishfyi@gmail.com (Anish Kr Singh) Wed, 29 Jul 2026 09:00:00 +0530 https://anishfyi.com/writings/why-i-hand-wrote-a-javascript-framework/ https://anishfyi.com/writings/why-i-hand-wrote-a-javascript-framework/ Alpine got the ergonomics right and stopped short on the engine. On fine-grained signals, a hand-written expression interpreter that survives a strict CSP, and what 16KB has to earn. Wed, 29 Jul 2026 09:00:00 +0530 Open Source TypeScript Frontend summit.js https://anishfyi.com/writings/why-your-scraper-gets-a-403/ https://anishfyi.com/writings/why-your-scraper-gets-a-403/ The block usually happens in the TLS handshake, before a single HTTP header is read. On JA3 fingerprints, self-healing selectors, and why I hand-wrote a crawl engine instead of importing Scrapy. Tue, 28 Jul 2026 09:00:00 +0530 Open Source Python Web Scraping curl_reap https://anishfyi.com/writings/parse-first-escalate-only-what-you-must/ https://anishfyi.com/writings/parse-first-escalate-only-what-you-must/ Most document pipelines throw the whole file at a model and bill you for the easy pages too. On rebuilding tables from word geometry, scoring yourself 0 to 1, and why the confidence score is the most important output. Mon, 27 Jul 2026 09:00:00 +0530 Open Source Python Applied AI terbium https://anishfyi.com/writings/querion-read-only-analyst/ https://anishfyi.com/writings/querion-read-only-analyst/ How I gave a language model production database access without ever letting it write: a read-only contract, a sandboxed directive loop, and a default-deny API allowlist. Sun, 14 Jun 2026 09:00:00 +0530 Open Source LLM Claude Code Postgres https://anishfyi.com/writings/trove-persistent-memory-claude-code/ https://anishfyi.com/writings/trove-persistent-memory-claude-code/ A file-based memory index that reloads into context every session, so Claude Code stops starting from zero and each session begins further ahead than the last. Wed, 10 Jun 2026 09:00:00 +0530 Open Source Claude Code Developer Tools https://anishfyi.com/writings/django-rest-framework-apis/ https://anishfyi.com/writings/django-rest-framework-apis/ How I structure serializers, views, and routers in Django REST Framework so API code stays predictable as a project grows. Tue, 12 May 2026 09:00:00 +0530 Django DRF API https://anishfyi.com/writings/order-state-machine/ https://anishfyi.com/writings/order-state-machine/ Turning a tangle of status flags into an explicit, testable state machine that guards every order transition. Tue, 28 Apr 2026 09:00:00 +0530 Django Architecture Patterns https://anishfyi.com/writings/hmac-webhook-verification/ https://anishfyi.com/writings/hmac-webhook-verification/ Why every inbound webhook needs a signature check, and how to verify HMAC payloads safely in Django. Tue, 14 Apr 2026 09:00:00 +0530 Webhooks Security Django https://anishfyi.com/writings/n-plus-one-queries/ https://anishfyi.com/writings/n-plus-one-queries/ Finding and fixing the silent N+1 queries that quietly add hundreds of milliseconds to an API response. Mon, 30 Mar 2026 09:00:00 +0530 Django ORM Performance https://anishfyi.com/writings/redis-caching-django/ https://anishfyi.com/writings/redis-caching-django/ A practical caching layer for read-heavy endpoints, covering cache keys, invalidation, and stampede protection. Mon, 16 Mar 2026 09:00:00 +0530 Redis Performance Django https://anishfyi.com/writings/celery-rabbitmq-jobs/ https://anishfyi.com/writings/celery-rabbitmq-jobs/ Moving slow work off the request path with Celery and RabbitMQ, with retries and idempotency that survive failure. Mon, 02 Mar 2026 09:00:00 +0530 Celery RabbitMQ Async https://anishfyi.com/writings/token-authentication-django/ https://anishfyi.com/writings/token-authentication-django/ Setting up token authentication for a Django API, from issuing tokens to rotating and revoking them. Mon, 16 Feb 2026 09:00:00 +0530 Django Auth Security https://anishfyi.com/writings/bulk-update-export-endpoints/ https://anishfyi.com/writings/bulk-update-export-endpoints/ Designing endpoints that update and export thousands of rows without timing out or locking the database. Mon, 02 Feb 2026 09:00:00 +0530 Django Performance API https://anishfyi.com/writings/django-signals/ https://anishfyi.com/writings/django-signals/ When Django signals keep code clean, when they hide bugs, and how to use them without regret. Mon, 19 Jan 2026 09:00:00 +0530 Django Patterns https://anishfyi.com/writings/zero-downtime-migrations/ https://anishfyi.com/writings/zero-downtime-migrations/ Shipping schema changes to a live Postgres database without dropped requests or downtime windows. Mon, 05 Jan 2026 09:00:00 +0530 Django Postgres Migrations https://anishfyi.com/writings/elasticsearch-django-search/ https://anishfyi.com/writings/elasticsearch-django-search/ Adding fast full-text search to a Django app by syncing models into Elasticsearch and querying them well. Mon, 15 Dec 2025 09:00:00 +0530 Elasticsearch Search Django https://anishfyi.com/writings/pdf-generation-reportlab/ https://anishfyi.com/writings/pdf-generation-reportlab/ Building clean, repeatable PDF documents like invoices and purchase orders directly from Django with ReportLab. Mon, 01 Dec 2025 09:00:00 +0530 Django PDF Python https://anishfyi.com/writings/testing-django-pytest/ https://anishfyi.com/writings/testing-django-pytest/ A pragmatic pytest setup for Django: fixtures, factories, database tests, and coverage that actually helps. Mon, 17 Nov 2025 09:00:00 +0530 Testing pytest Django https://anishfyi.com/writings/production-observability/ https://anishfyi.com/writings/production-observability/ Wiring Sentry, Prometheus, and Grafana into a Django service so production tells you when it hurts. Mon, 03 Nov 2025 09:00:00 +0530 Observability Monitoring DevOps https://anishfyi.com/writings/dockerizing-django/ https://anishfyi.com/writings/dockerizing-django/ A Docker setup for Django that stays fast in local development and lean in production. Mon, 20 Oct 2025 09:00:00 +0530 Docker DevOps Django