https://darshanturakhia.com/blog Full-stack architecture, systems engineering, and developer insights by Darshan Turakhia. en-us https://darshanturakhia.com/blog/from-vercel-to-aws-part-3-migration https://darshanturakhia.com/blog/from-vercel-to-aws-part-3-migration The migration decision is not technical. It is financial. At $6k/month in platform costs, the AWS equivalent saves $4k. Here is the exact sequence to move without stopping product work. Sat, 04 Jul 2026 00:00:00 GMT Architecture https://darshanturakhia.com/blog/from-vercel-to-aws-part-2-breaking-points https://darshanturakhia.com/blog/from-vercel-to-aws-part-2-breaking-points Your Supabase connection pool is full at 3 AM. Vercel cold starts are appearing in your P99. Railway is CPU-throttling your worker. Not all at once — each signal arrives weeks apart. Here is how to read them. Fri, 03 Jul 2026 00:00:00 GMT Architecture https://darshanturakhia.com/blog/from-vercel-to-aws-part-1-the-stack https://darshanturakhia.com/blog/from-vercel-to-aws-part-1-the-stack A three-person team ships a B2B SaaS in four weeks with Vercel, Supabase, Railway, and Upstash. Total monthly cost: $47. Three months later it's still holding at 200 customers. This is not an accident. Thu, 02 Jul 2026 00:00:00 GMT Architecture https://darshanturakhia.com/blog/agents-in-production-part-3-enterprise https://darshanturakhia.com/blog/agents-in-production-part-3-enterprise Thirty teams, each running agents independently. One shared LLM quota. No visibility across team boundaries. The cost bill triples in sixty days and nobody knows why. Wed, 01 Jul 2026 00:00:00 GMT Architecture https://darshanturakhia.com/blog/agents-in-production-part-2-scaleup https://darshanturakhia.com/blog/agents-in-production-part-2-scaleup Multi-step agent chains break in ways single LLM calls do not. When step 3 fails, you have no idea which step produced bad data, and retries re-run everything from the start. Sat, 27 Jun 2026 00:00:00 GMT Architecture https://darshanturakhia.com/blog/event-driven-architecture-patterns https://darshanturakhia.com/blog/event-driven-architecture-patterns Domain events, event sourcing, the outbox pattern, and consumer groups — the event-driven patterns I use in production and the tradeoffs you need to understand before adopting them. Sat, 27 Jun 2026 00:00:00 GMT Architecture https://darshanturakhia.com/blog/agents-in-production-part-1-startup https://darshanturakhia.com/blog/agents-in-production-part-1-startup Most startups already have the queue-based foundation LLMs need. The problem is how they wire the LLM in — synchronously, inline, with no fallback. Fri, 26 Jun 2026 00:00:00 GMT Architecture https://darshanturakhia.com/blog/nodejs-stream-processing https://darshanturakhia.com/blog/nodejs-stream-processing Node.js streams pipe data through transforms without buffering. Here is the practical pattern for CSV processing, HTTP responses, and file transformations. Wed, 10 Jun 2026 00:00:00 GMT NodeJS https://darshanturakhia.com/blog/fastapi-websocket-realtime https://darshanturakhia.com/blog/fastapi-websocket-realtime FastAPI has first-class WebSocket support. Here is the complete pattern for connection management, broadcasting to rooms, and handling reconnections. Sun, 07 Jun 2026 00:00:00 GMT Python https://darshanturakhia.com/blog/postgres-materialized-views-refresh https://darshanturakhia.com/blog/postgres-materialized-views-refresh Materialized views pre-compute expensive queries and store the results. With CONCURRENTLY refresh, you get zero-downtime updates. Here is the complete pattern. Sat, 06 Jun 2026 00:00:00 GMT Database https://darshanturakhia.com/blog/nextjs-image-component-optimization https://darshanturakhia.com/blog/nextjs-image-component-optimization Beyond basic usage, the Next.js Image component has placeholder blurs, priority loading, art direction with different sizes, and fill mode for responsive containers. Fri, 05 Jun 2026 00:00:00 GMT React https://darshanturakhia.com/blog/claude-regex-pattern-generator https://darshanturakhia.com/blog/claude-regex-pattern-generator Regex is powerful and unreadable. I use Claude to generate patterns from plain English, explain existing ones, and build test suites — all without opening a regex reference. Fri, 05 Jun 2026 00:00:00 GMT Claude https://darshanturakhia.com/blog/claude-system-design-interview-prep https://darshanturakhia.com/blog/claude-system-design-interview-prep Claude can roleplay as a skeptical interviewer who pushes back on your design decisions. Here is the exact setup that makes the practice sessions feel like real interviews. Thu, 04 Jun 2026 00:00:00 GMT Claude https://darshanturakhia.com/blog/claude-structured-output-api-design https://darshanturakhia.com/blog/claude-structured-output-api-design Using a dummy tool call to force Claude to return structured JSON is more reliable than prompt-based instructions. Here is the pattern with real examples. Wed, 03 Jun 2026 00:00:00 GMT Claude https://darshanturakhia.com/blog/claude-sql-query-optimizer https://darshanturakhia.com/blog/claude-sql-query-optimizer The prompt pattern that gets Claude to rewrite slow SQL with CTEs, proper indexes, and query plan analysis — turning 8-second queries into 200ms ones. Sat, 30 May 2026 00:00:00 GMT Claude https://darshanturakhia.com/blog/claude-projects-team-onboarding https://darshanturakhia.com/blog/claude-projects-team-onboarding Claude Projects with the right context files turns new engineer onboarding from a week-long process into a few focused hours. Here is exactly what I put in each project. Fri, 29 May 2026 00:00:00 GMT Claude https://darshanturakhia.com/blog/webmcp-browser-ai-agents-standard https://darshanturakhia.com/blog/webmcp-browser-ai-agents-standard Google's WebMCP lets sites expose structured tools so browser agents skip the DOM guessing and call functions directly. Chrome 149 origin trial opens June 2. Sat, 30 May 2026 00:00:00 GMT Web https://darshanturakhia.com/blog/gemini-flash-agentic-loops-latency https://darshanturakhia.com/blog/gemini-flash-agentic-loops-latency A Claude-based code review agent was taking 36 seconds per request — 12 steps at 3 seconds each. Switching the inner loop to Gemini 3.5 Flash cut it to under 10 seconds with no quality drop. Wed, 03 Jun 2026 00:00:00 GMT Gemini https://darshanturakhia.com/blog/claude-opus-4-8-released https://darshanturakhia.com/blog/claude-opus-4-8-released Claude Opus 4.8: 96.7% on USAMO math, 88.6% SWE-bench Verified, 0% silent flaw rate. Full breakdown of benchmarks, new features, and what it means for engineers. Fri, 29 May 2026 00:00:00 GMT AI https://darshanturakhia.com/blog/gemini-audio-video-pipeline-simplification https://darshanturakhia.com/blog/gemini-audio-video-pipeline-simplification Running audio through Whisper then GPT-4 was two API calls, two billing accounts, and a temp file in the middle. Gemini accepts the audio directly and returns structured output. Sun, 17 May 2026 00:00:00 GMT Gemini https://darshanturakhia.com/blog/gemini-1m-context-window-large-codebase https://darshanturakhia.com/blog/gemini-1m-context-window-large-codebase After hitting Claude's 200K limit on a 300K-token codebase, I switched to Gemini and fed the whole thing at once. Here's what changed. Sat, 16 May 2026 00:00:00 GMT Gemini https://darshanturakhia.com/blog/gemini-25-models-guide https://darshanturakhia.com/blog/gemini-25-models-guide Google released Gemini 3.5 Flash at I/O 2026 and it outperforms Gemini 3.1 Pro on 11 of 15 benchmarks. Here is a breakdown of what changed, where it wins, and where 3.1 Pro still holds. Fri, 15 May 2026 00:00:00 GMT Gemini https://darshanturakhia.com/blog/claude-pr-description-two-minutes https://darshanturakhia.com/blog/claude-pr-description-two-minutes I wrote a shell alias that pipes git diff to Claude and gets a structured PR description back. The whole workflow takes under two minutes and reviewers actually thank me now. Thu, 28 May 2026 00:00:00 GMT Claude https://darshanturakhia.com/blog/claude-openapi-spec-from-codebase https://darshanturakhia.com/blog/claude-openapi-spec-from-codebase I had 40 undocumented API endpoints. Claude read the route handlers and generated a complete OpenAPI 3.1 spec in one afternoon. Here is the workflow. Wed, 27 May 2026 00:00:00 GMT Claude https://darshanturakhia.com/blog/claude-monorepo-navigation https://darshanturakhia.com/blog/claude-monorepo-navigation A three-layer context strategy for using Claude on large codebases — global map, service summary, and targeted file context — that fits within any context window. Sat, 23 May 2026 00:00:00 GMT Claude https://darshanturakhia.com/blog/claude-mcp-custom-server-build https://darshanturakhia.com/blog/claude-mcp-custom-server-build The Model Context Protocol lets you give Claude access to any tool, database, or API. Here is the exact pattern I use to build MCP servers in under an hour. Sat, 23 May 2026 00:00:00 GMT Claude https://darshanturakhia.com/blog/claude-infrastructure-as-code-review https://darshanturakhia.com/blog/claude-infrastructure-as-code-review A pre-apply Claude review of Terraform plans catches security misconfigurations, overly permissive IAM policies, and missing deletion protection that human reviewers routinely miss. Mon, 18 May 2026 00:00:00 GMT Claude https://darshanturakhia.com/blog/claude-dependency-audit-workflow https://darshanturakhia.com/blog/claude-dependency-audit-workflow A workflow that uses Claude to analyze breaking changes, identify risky dependencies, and generate a prioritized upgrade plan — before you run npm update. Sun, 17 May 2026 00:00:00 GMT Claude https://darshanturakhia.com/blog/claude-debugging-think-mode https://darshanturakhia.com/blog/claude-debugging-think-mode Extended thinking gives Claude time to reason through complex, multi-layer bugs before answering. Here is when to use it and the prompt structure that works best. Sun, 17 May 2026 00:00:00 GMT Claude https://darshanturakhia.com/blog/claude-data-pipeline-design https://darshanturakhia.com/blog/claude-data-pipeline-design The iterative Claude workflow that turns a rough product requirement into a complete ETL pipeline design with schema, error handling, and monitoring strategy. Wed, 06 May 2026 00:00:00 GMT Claude https://darshanturakhia.com/blog/claude-context-window-strategy https://darshanturakhia.com/blog/claude-context-window-strategy A 200K context window is powerful but expensive if you fill it carelessly. Here are the strategies I use to send the right context, not all the context. Thu, 30 Apr 2026 00:00:00 GMT Claude https://darshanturakhia.com/blog/claude-code-review-workflow https://darshanturakhia.com/blog/claude-code-review-workflow A structured prompt that uses Claude to review code for security issues, performance problems, and API design consistency — the things humans skip when tired. Sat, 25 Apr 2026 00:00:00 GMT Claude https://darshanturakhia.com/blog/claude-changelog-generation https://darshanturakhia.com/blog/claude-changelog-generation A script that turns raw git log into polished, user-facing changelogs grouped by type. Takes 30 seconds instead of 30 minutes before every release. Thu, 23 Apr 2026 00:00:00 GMT Claude https://darshanturakhia.com/blog/claude-batch-api-background-tasks https://darshanturakhia.com/blog/claude-batch-api-background-tasks The Message Batches API processes up to 10,000 requests asynchronously at half the price. Perfect for document processing, classification, and content generation jobs. Thu, 23 Apr 2026 00:00:00 GMT Claude https://darshanturakhia.com/blog/claude-api-documentation-from-code https://darshanturakhia.com/blog/claude-api-documentation-from-code The prompt that turns a raw TypeScript function signature into complete API documentation with examples, error descriptions, and edge case notes. Thu, 16 Apr 2026 00:00:00 GMT Claude https://darshanturakhia.com/blog/postgres-lateral-joins-replaced-loops https://darshanturakhia.com/blog/postgres-lateral-joins-replaced-loops Four nested Python loops. One slow endpoint. I replaced all of it with one Postgres LATERAL join. Most backend devs don't know it exists. Wed, 15 Apr 2026 00:00:00 GMT Database https://darshanturakhia.com/blog/fastapi-depends-pattern-every-project https://darshanturakhia.com/blog/fastapi-depends-pattern-every-project Tutorials show you Depends() in week 1. Nobody shows you composition until your auth is already a mess. The 4-day refactor I could have skipped. Sat, 11 Apr 2026 00:00:00 GMT Python https://darshanturakhia.com/blog/react-query-replaced-redux-server-state https://darshanturakhia.com/blog/react-query-replaced-redux-server-state The server state vs client state distinction that React Query makes explicit replaced my need for Redux entirely. Here is the mental model shift. Fri, 10 Apr 2026 00:00:00 GMT React https://darshanturakhia.com/blog/nextjs-server-actions-removed-api-layer https://darshanturakhia.com/blog/nextjs-server-actions-removed-api-layer Profile, notifications, settings — 3 routes I deleted last month. Server Actions made them obsolete and most teams haven't noticed yet. Thu, 09 Apr 2026 00:00:00 GMT React https://darshanturakhia.com/blog/claude-extended-thinking-debug-complex-bugs https://darshanturakhia.com/blog/claude-extended-thinking-debug-complex-bugs Most engineers use Claude like a search engine. Turn on extended thinking and it reasons through your problem like a senior engineer thinking out loud — the difference is remarkable. Fri, 03 Apr 2026 00:00:00 GMT Claude https://darshanturakhia.com/blog/react-eliminate-useeffect-derived-state https://darshanturakhia.com/blog/react-eliminate-useeffect-derived-state Most useEffect calls are just bad data derivation. Here is the derived state pattern that cleaned up years of accumulated complexity in my React components. Wed, 08 Apr 2026 00:00:00 GMT React https://darshanturakhia.com/blog/claude-tool-use-pattern-every-project https://darshanturakhia.com/blog/claude-tool-use-pattern-every-project The exact function calling pattern for Claude tools — structured output, error handling, retries — that saves 2 hours per project. Here is the reusable ToolRunner class. Sat, 04 Apr 2026 00:00:00 GMT Claude https://darshanturakhia.com/blog/claude-boilerplate-from-comment https://darshanturakhia.com/blog/claude-boilerplate-from-comment The prompting pattern that generates production-ready code with type hints, error handling, and tests — from a single comment. The secret is not the prompt itself. Fri, 03 Apr 2026 00:00:00 GMT Claude https://darshanturakhia.com/blog/claude-codebase-context-what-i-built https://darshanturakhia.com/blog/claude-codebase-context-what-i-built Most engineers use Claude for snippets. I started feeding it my entire repo — and it changed how I do architecture reviews, refactors, and onboarding. Thu, 02 Apr 2026 00:00:00 GMT Claude https://darshanturakhia.com/blog/claude-prompt-caching-cut-ai-costs https://darshanturakhia.com/blog/claude-prompt-caching-cut-ai-costs Most engineers send the full context on every Claude API call. There's a built-in feature that changes that — and most people have never heard of it. Tue, 31 Mar 2026 00:00:00 GMT Claude https://darshanturakhia.com/blog/mcp-server-prod-db-write-access-incident https://darshanturakhia.com/blog/mcp-server-prod-db-write-access-incident A misconfigured Model Context Protocol server quietly connected our AI coding assistant directly to production PostgreSQL. For 11 days it only read. On day 12 it wrote — and we noticed too late. Sat, 28 Mar 2026 00:00:00 GMT Security https://darshanturakhia.com/blog/prompt-injection-ai-agent-data-leak https://darshanturakhia.com/blog/prompt-injection-ai-agent-data-leak Our AI support agent was exfiltrating customer ticket data for three days before a cost anomaly alert fired. Here is what we missed and how we fixed it. Fri, 27 Mar 2026 00:00:00 GMT Security https://darshanturakhia.com/blog/ai-rate-limiter-zero-rps https://darshanturakhia.com/blog/ai-rate-limiter-zero-rps We built an AI-powered adaptive rate limiter that monitored traffic patterns and adjusted limits automatically. At 2:07 AM on a Saturday, it analyzed an anomalous traffic spike, classified it as a DDoS attack, and set our public API rate limit to 0 requests per second. It was our own mobile app doing a scheduled sync. Fri, 27 Mar 2026 00:00:00 GMT AI https://darshanturakhia.com/blog/claude-wrote-db-migrations-deleted-data https://darshanturakhia.com/blog/claude-wrote-db-migrations-deleted-data We used Claude to clean up deprecated columns from our users table. The migration ran in 180ms. What we didn't know: a billing service in a separate repo was still reading those columns. 3,200 invoices went out with blank shipping addresses before anyone noticed. Recovery took 14 hours. Thu, 26 Mar 2026 00:00:00 GMT AI https://darshanturakhia.com/blog/ai-pr-reviewer-approved-bug https://darshanturakhia.com/blog/ai-pr-reviewer-approved-bug We integrated GPT-4 as an automated code reviewer into our GitHub Actions pipeline. Over 30 days it caught 61 real issues. Then it approved a subtle auth bypass that left 23 admin routes unprotected for 11 days — because the bug lived across three files that were never in the diff. Wed, 25 Mar 2026 00:00:00 GMT AI https://darshanturakhia.com/blog/nextjs-middleware-edge-auth-bypass https://darshanturakhia.com/blog/nextjs-middleware-edge-auth-bypass After migrating to Next.js 15 App Router, our JWT verification middleware silently failed on Edge Runtime — leaving 23 admin API routes accessible without a valid token for 11 days before a security audit caught it. Tue, 24 Mar 2026 00:00:00 GMT Security https://darshanturakhia.com/blog/kafka-offset-reset-duplicate-payments https://darshanturakhia.com/blog/kafka-offset-reset-duplicate-payments A single Kafka offset reset to --to-earliest replayed 3 hours of payment events on a live consumer group. Here is exactly what happened and how we fixed it. Sat, 21 Mar 2026 00:00:00 GMT Architecture https://darshanturakhia.com/blog/react-native-codepush-bundle-corruption-40k-users https://darshanturakhia.com/blog/react-native-codepush-bundle-corruption-40k-users We pushed a JavaScript bundle via CodePush — no app store review, instant delivery, zero validation. By the time Sentry caught it, 40,000 users had a white screen and no clean rollback path existed. Sat, 21 Mar 2026 00:00:00 GMT Mobile https://darshanturakhia.com/blog/blue-green-column-rename-data-corruption https://darshanturakhia.com/blog/blue-green-column-rename-data-corruption We had blue-green deployments, health checks, and automatic rollbacks. Then a single column rename executed during the deploy window and our old containers spent 11 minutes writing to a column that no longer existed. Tue, 17 Mar 2026 00:00:00 GMT CI/CD https://darshanturakhia.com/blog/ai-dropped-wrong-index-migration-query-spike https://darshanturakhia.com/blog/ai-dropped-wrong-index-migration-query-spike We asked an AI coding assistant to clean up redundant PostgreSQL indexes. It dropped the wrong one. API latency jumped from 3ms to 45 seconds. Here is what a 3.5-hour investigation taught us about trusting AI with schema changes. Tue, 17 Mar 2026 00:00:00 GMT AI https://darshanturakhia.com/blog/ecs-autoscaling-postgres-max-connections https://darshanturakhia.com/blog/ecs-autoscaling-postgres-max-connections We scaled to 38 ECS tasks during a flash sale. Each task held 10 Postgres connections. Our RDS instance allowed 170. The math was never going to work. Mon, 16 Mar 2026 00:00:00 GMT Database https://darshanturakhia.com/blog/ai-agent-k8s-resource-limits-oom-cascade https://darshanturakhia.com/blog/ai-agent-k8s-resource-limits-oom-cascade We let a Cursor AI agent refactor our Kubernetes deployment files to remove boilerplate. Six hours later, 34% of requests were failing as pods OOMKilled faster than they could restart. Sun, 15 Mar 2026 00:00:00 GMT AI https://darshanturakhia.com/blog/rag-embedding-model-upgrade-silent-wrong-results https://darshanturakhia.com/blog/rag-embedding-model-upgrade-silent-wrong-results We upgraded from text-embedding-ada-002 to text-embedding-3-large without re-embedding our 2.3M documents. Cosine similarity searches silently returned wrong content for six days — valid JSON, HTTP 200, completely wrong answers. Sun, 15 Mar 2026 00:00:00 GMT AI https://darshanturakhia.com/blog/env-file-47-forks-junior-dev-pr https://darshanturakhia.com/blog/env-file-47-forks-junior-dev-pr A junior developer forked our private repo to submit a bug fix, unknowingly committed our .env file, and GitHub indexed it. We had production credentials exposed in 47 public forks before anyone noticed. Mon, 16 Mar 2026 00:00:00 GMT Security https://darshanturakhia.com/blog/gpt4-nondeterminism-broke-ci-pipeline https://darshanturakhia.com/blog/gpt4-nondeterminism-broke-ci-pipeline We built an automated code review pipeline that used GPT-4 with temperature=0 to enforce consistent output. After OpenAI silently updated the model behind the same API endpoint, our determinism assumption collapsed — tests started flipping between pass and fail on identical inputs, and we couldn't reproduce failures locally. Wed, 18 Mar 2026 00:00:00 GMT AI https://darshanturakhia.com/blog/openai-bill-4200-dollars-missing-stop-token https://darshanturakhia.com/blog/openai-bill-4200-dollars-missing-stop-token We built a feedback-processing pipeline that used GPT-4 to categorise and summarise user feedback. A single missing stop sequence caused the model to loop indefinitely, generating 40-million tokens of circular output over a holiday weekend while our alerts stayed quiet. Tue, 17 Mar 2026 00:00:00 GMT AI https://darshanturakhia.com/blog/llm-hallucinated-api-routes-production https://darshanturakhia.com/blog/llm-hallucinated-api-routes-production We shipped an LLM-powered documentation assistant trained on our API docs. Within three weeks, it had confidently hallucinated 14 non-existent endpoints. Developers built integrations against them. Support tickets arrived. We had to choose between breaking those integrations or actually building the routes the AI had promised. Mon, 16 Mar 2026 00:00:00 GMT AI https://darshanturakhia.com/blog/github-actions-cache-test-skip-regression https://darshanturakhia.com/blog/github-actions-cache-test-skip-regression Our CI pipeline showed green for six consecutive deploys while never running the new test files we added. A cache key tied only to package-lock.json silently restored stale compiled test artifacts — new tests never compiled, never ran, and a broken discount-code checkout reached production for 6 hours. Sun, 15 Mar 2026 00:00:00 GMT CI/CD https://darshanturakhia.com/blog/postgres-not-null-migration-table-lock https://darshanturakhia.com/blog/postgres-not-null-migration-table-lock A routine schema migration to add a NOT NULL column with a default value triggered a full table rewrite in Postgres, holding an exclusive lock on 2.4 million rows and taking our entire platform offline for 14 minutes at 10 AM on a Monday. Sun, 15 Mar 2026 00:00:00 GMT Database https://darshanturakhia.com/blog/flask-sqlalchemy-scoped-session-stale-reads https://darshanturakhia.com/blog/flask-sqlalchemy-scoped-session-stale-reads We managed SQLAlchemy sessions manually in Flask, skipping Flask-SQLAlchemy. Forgetting one line — Session.remove() — turned the ORM's per-thread identity map into a stale-data cache that silently returned outdated records for six hours. Sun, 15 Mar 2026 00:00:00 GMT Python https://darshanturakhia.com/blog/sqs-visibility-timeout-order-duplication https://darshanturakhia.com/blog/sqs-visibility-timeout-order-duplication A production war story about how a 30-second SQS visibility timeout turned a slow order processor into a duplicate-charge machine — and how we fixed it with heartbeats and a distributed lock. Sat, 14 Mar 2026 00:00:00 GMT Architecture https://darshanturakhia.com/blog/cron-race-condition-duplicate-emails https://darshanturakhia.com/blog/cron-race-condition-duplicate-emails A nightly email digest cron job was running on two servers simultaneously without a distributed lock — what started as a minor scheduling overlap turned into a 2.3 million email catastrophe that got our domain blacklisted before sunrise. Sat, 14 Mar 2026 00:00:00 GMT Architecture https://darshanturakhia.com/blog/nextjs-15-full-route-cache-stale-checkout https://darshanturakhia.com/blog/nextjs-15-full-route-cache-stale-checkout After migrating a SaaS checkout flow to Next.js 15 App Router, our price display layer silently served cached values — not the live database prices — costing us 3 hours of confused customers and 19 manual refunds. Sat, 14 Mar 2026 00:00:00 GMT Architecture https://darshanturakhia.com/blog/mobile-push-fanout-pool-exhaustion https://darshanturakhia.com/blog/mobile-push-fanout-pool-exhaustion A synchronous push notification fanout loop for a user with 45,000 followers exhausted our Flask database connection pool in 90 seconds, failing 62% of mobile requests for 3 hours. Sat, 14 Mar 2026 00:00:00 GMT Mobile https://darshanturakhia.com/blog/jwt-secret-rotation-outage https://darshanturakhia.com/blog/jwt-secret-rotation-outage A routine security rotation invalidated every active session simultaneously, triggered a support flood, and revealed that our JWT architecture had no graceful degradation path whatsoever. Fri, 13 Mar 2026 00:00:00 GMT Security https://darshanturakhia.com/blog/digitalocean-firewall-silent-drop https://darshanturakhia.com/blog/digitalocean-firewall-silent-drop Intermittent user timeouts, normal server metrics, and zero firewall logs — how a stateless firewall rule was killing TCP connections before they reached Nginx, and why it took eleven days to find it. Fri, 13 Mar 2026 00:00:00 GMT Docker https://darshanturakhia.com/blog/multitenant-cache-poisoning https://darshanturakhia.com/blog/multitenant-cache-poisoning A SaaS platform cached API responses by resource ID alone — when two tenants happened to share the same integer ID, one client spent three days reading another's confidential records. Thu, 12 Mar 2026 00:00:00 GMT Architecture https://darshanturakhia.com/blog/docker-ecs-memory-leak-cascade https://darshanturakhia.com/blog/docker-ecs-memory-leak-cascade A Redis client spawned inside getServerSideProps accumulated 8,847 open connections over six hours, OOM-killed every ECS task, and took the service down for 47 minutes before we found the root cause. Thu, 12 Mar 2026 00:00:00 GMT Docker https://darshanturakhia.com/blog/react-usecallback-api-storm https://darshanturakhia.com/blog/react-usecallback-api-storm A React search component's unstable function reference created an infinite useEffect loop that sent 10,400 req/min to our backend until the rate-limiter started blacklisting our own users. Wed, 11 Mar 2026 00:00:00 GMT React https://darshanturakhia.com/blog/fastapi-shared-state-trap https://darshanturakhia.com/blog/fastapi-shared-state-trap We replaced Flask's request-scoped g with a plain dict during migration. Under async concurrency, that dict silently served one tenant's data to a completely different user. Wed, 11 Mar 2026 00:00:00 GMT Python https://darshanturakhia.com/blog/nodejs-event-loop-invisible-bottleneck https://darshanturakhia.com/blog/nodejs-event-loop-invisible-bottleneck A single fs.readFileSync buried in a utility function seemed harmless in development — in production under real traffic, it silently froze every request in the system for 700ms at a time. Tue, 10 Mar 2026 00:00:00 GMT NodeJS https://darshanturakhia.com/blog/php-to-nextjs-the-migration-nobody-warned-us-about https://darshanturakhia.com/blog/php-to-nextjs-the-migration-nobody-warned-us-about What looked like a clean strangler-fig migration turned into 18 months of session bridges, soft-delete mismatches, and hard lessons about the implicit contracts hiding inside every legacy codebase. Mon, 09 Mar 2026 00:00:00 GMT Architecture https://darshanturakhia.com/blog/postgres-the-query-that-killed-production https://darshanturakhia.com/blog/postgres-the-query-that-killed-production A four-line SQL query worked perfectly in development — in production, with 8 million rows, it held the database hostage for 47 minutes and took down an entire SaaS platform on a Friday afternoon. Sat, 07 Mar 2026 00:00:00 GMT Database https://darshanturakhia.com/blog/deploy-friday-never-again https://darshanturakhia.com/blog/deploy-friday-never-again A production deploy at 4:30 PM on a Friday turned a routine release into a 6-hour incident — and permanently changed how I think about automation and discipline. Thu, 05 Mar 2026 00:00:00 GMT CI/CD https://darshanturakhia.com/blog/elasticsearch-the-night-the-cluster-went-silent https://darshanturakhia.com/blog/elasticsearch-the-night-the-cluster-went-silent It was 11:47 PM. Search was down. 40,000 users couldn't find anything. This is the story of how a single shard misconfiguration quietly ate our cluster — and what we learned after rebuilding it from scratch. Tue, 03 Mar 2026 00:00:00 GMT ElasticSearch