# Arsalan Sheikh (cybars69) > Arsalan Sheikh (cybars69) is a full-stack engineer from Kashmir. Platforms, AI agents, integrations and automation, plus open-source agent skills and the odd generative-art experiment. Every page has a Markdown version: add `.md` to the URL (`/blog/x/` becomes `/blog/x.md`, the home page is `/index.md`). ## Pages - [Home](https://cybars69.github.io/index.md): about, experience, skills, selected work - [Tools](https://cybars69.github.io/tools.md): tools grouped by area, with what each was used for - [Projects](https://cybars69.github.io/projects.md): open source, anonymized studio work, side projects - [Blog](https://cybars69.github.io/blog.md): technical write-ups - [Links](https://cybars69.github.io/links.md): profiles and résumé - [Contact](https://cybars69.github.io/contact.md) ## Projects - [aeo-skills](https://cybars69.github.io/projects/aeo-skills.md): Open-source agent skills that audit, rewrite and monitor whether answer engines can extract a clean answer from your pages. - [Generative art](https://cybars69.github.io/projects/generative-art.md): Generative art pieces with P5JS. - [Word2Video](https://cybars69.github.io/projects/word2video.md): Takes every instance of a word in a PDF and turns the frames into a video with ffmpeg. - [BLE image transfer](https://cybars69.github.io/projects/ble-image-transfer.md): Transfers an image from the browser over Web Bluetooth to an e-paper display. - [Image channel splitter](https://cybars69.github.io/projects/image-channel-splitter.md): Splits an image into separate RGB channels. - [Nonslop Sidebar](https://cybars69.github.io/projects/nonslop-sidebar.md): A UX-first sidebar navigation skill for AI coding agents. Accessible, responsive, and actually usable. - [White-label commerce platform](https://cybars69.github.io/projects/commerce-platform.md): A multi-tenant storefront platform where every store gets its own Worker, plans are signed entitlements, and AI agents can run the shop over MCP. - [Concentration prediction](https://cybars69.github.io/projects/concentration-prediction.md): Protein concentration prediction with ML, served over the college intranet through FastAPI. - [Telanon](https://cybars69.github.io/projects/telanon.md): Send anonymous messages to people. - [WhatsApp booking agent](https://cybars69.github.io/projects/booking-agent.md): A multi-tenant chatbot that answers customers and takes bookings on WhatsApp, rebuilt from a framework-heavy agent into plain Python and raw API calls. - [Web cloner](https://cybars69.github.io/projects/web-cloner.md): Clone the entire structure of index-of.es. - [Hospitality marketplace](https://cybars69.github.io/projects/hospitality-marketplace.md): A stays marketplace for a remote valley in Kashmir: search, booking, payments, payouts, and separate customer, merchant and admin apps. - [Valor Tutors](https://cybars69.github.io/projects/valor-tutors.md): A website for a tutoring institute across the Kashmir Valley. - [White-label LMS](https://cybars69.github.io/projects/lms-platform.md): A learning platform with courses, pathways and quizzes, deployed once per customer on Cloudflare Workers with its own database. - [Storefront on Workers](https://cybars69.github.io/projects/storefront-on-workers.md): A small storefront built to live inside Cloudflare's free tier: React, Hono, Workers KV and Stripe, with a repo designed for coding agents. - [Healthcare supply platform](https://cybars69.github.io/projects/healthcare-logistics.md): Portals for clinics, distributors and riders plus a patient mobile app, on one backend with tenant-scoped access and its own observability stack. - [Work-order board](https://cybars69.github.io/projects/work-order-board.md): A deliberately minimal order system for a print shop. One work order, shared tasks, and workers who pick things up themselves. - [Clinic site and lead pipeline](https://cybars69.github.io/projects/clinic-lead-pipeline.md): A clinic website that publishes an MCP server for AI assistants, and a lead pipeline that connects ad clicks to revenue. - [AI interview practice](https://cybars69.github.io/projects/interview-practice.md): A voice interview simulator with resume-aware questions, timed sessions and full transcripts. Eighteen iterations, some of them failures worth writing about. - [Billing tracker](https://cybars69.github.io/projects/billing-tracker.md): An internal tool for clients, projects, invoices and a small ledger, with dashboards and branded exports for accountants. - [Agency site and GEO audit](https://cybars69.github.io/projects/agency-site-geo.md): An Astro marketing site for a services agency, and the audit that showed a perfect on-page score does not rank a young domain. ## Blog - [A GEO audit is a checklist, not a ranking model](https://cybars69.github.io/blog/geo-audit-checklist-not-ranking-model.md): What an audit of a young marketing site found, and why fixing every point on the checklist still wouldn't have moved it off page six. - [A shop on a key-value store: index arrays, immutable Stripe prices and what you give up](https://cybars69.github.io/blog/a-shop-on-a-key-value-store.md): Modelling products and collections in Workers KV, syncing them to Stripe without breaking history, and the reliability limits of a store with no queries. - [Demo mode as signed config, not a fork](https://cybars69.github.io/blog/demo-mode-as-signed-config.md): Ephemeral public demo stores that can't send email, take payments or be crawled, driven by one flag in the same signed document as everything else. - [Direct-to-R2 uploads with presigned PUTs: presign, PUT, confirm](https://cybars69.github.io/blog/presigned-uploads-to-r2.md): Files go from the browser straight to object storage. The server issues a URL, then trusts nothing until the client confirms. - [Dropping the agent framework](https://cybars69.github.io/blog/dropping-the-agent-framework.md): Rebuilding a multi-tenant WhatsApp chatbot with a cheap classifier, a plain router and raw API calls instead of an agent framework. - [iCal is not a channel manager: what ARI restrictions are and why a booking engine needs them](https://cybars69.github.io/blog/ical-is-not-a-channel-manager.md): An audit of a stays marketplace against what a real online travel agency needs, and the availability, rates and inventory model behind it. - [Modelling quizzes: question types, manual grading and the attempt state you didn't know you needed](https://cybars69.github.io/blog/modelling-quizzes-question-types-and-attempt-states.md): What I learned by reading the source of a mature open-source LMS plugin before designing a quiz schema. - [Observability that lives outside the app stack](https://cybars69.github.io/blog/observability-outside-the-app-stack.md): Grafana, Loki, Promtail, Prometheus, cAdvisor and node_exporter as their own compose stack, joined to the app only by a shared network. - [One state machine for work orders: deleting the workflow](https://cybars69.github.io/blog/one-state-machine-for-work-orders.md): A print shop's order system with a single three-state task machine, an atomic pickup, a delivery gate and a signed customer ledger. - [OTP login, refresh-token families and three layers of access for multi-tenant portals](https://cybars69.github.io/blog/otp-auth-for-multi-tenant-portals.md): One identity system for patients, clinic staff, distributors and admins: challenge-based OTP in Redis, rotating refresh tokens, and access that is checked in three separate layers. - [Plans that never block checkout](https://cybars69.github.io/blog/plans-that-never-block-checkout.md): Designing subscription tiers for a multi-tenant commerce platform so that billing state can never take a store's checkout offline. - [Provisioning a WhatsApp number in six steps](https://cybars69.github.io/blog/provisioning-a-whatsapp-number-in-six-steps.md): Twilio subaccounts, a Chatwoot account, an agent bot, an inbox and a Meta embedded signup, wired into one onboarding flow. - [Rebuilt this site with Astro](https://cybars69.github.io/blog/rebuilt-with-astro.md): Why the site moved from hand-written HTML to Astro, and how it deploys from a docs folder. - [Signed entitlements over KV: Ed25519, a five-step fallback chain, and a document that can only narrow](https://cybars69.github.io/blog/signed-entitlements-over-kv.md): How a store Worker learns what it may do without ever learning what a plan is called, and why every failure path resolves to the shop still selling. - [Streaming microphone audio from a browser, in three attempts](https://cybars69.github.io/blog/streaming-mic-audio-three-attempts.md): WebM chunks, WAV, decoded PCM and finally an AudioWorklet. What broke, why, and what the two failed write-ups got wrong. - [The control-plane seam: idempotent usage snapshots, an event outbox and HMAC commands](https://cybars69.github.io/blog/control-plane-seam-usage-events-hmac.md): How a per-tenant Worker and a central control plane talk to each other safely over unreliable networks, with no queue infrastructure. - [The repo is the system of record](https://cybars69.github.io/blog/repo-as-system-of-record.md): Setting up a small codebase so that both people and coding agents can work in it reliably, without a 500-line instruction file. - [The webhook returns 200 first: a WhatsApp agent's message pipeline, tool loop and human handoff](https://cybars69.github.io/blog/the-webhook-returns-200-first.md): What happens between a customer's message and the reply: filtering, acknowledging early, classifying, routing, a tool loop, a silent fallback and a four-call escalation. - [Two currencies, one invoice: keeping subscription billing and shopper commerce apart](https://cybars69.github.io/blog/two-currencies-one-invoice.md): A multi-tenant platform that bills merchants in one currency while their shoppers pay in another, and the bugs that appear when the two share a field. - [Why my WebSocket kept disconnecting](https://cybars69.github.io/blog/websocket-pings-blocked-event-loop.md): Ping timeouts, restarting sessions and rapid reconnect loops. The fix wasn't a timeout setting; it was a blocking call. ## Optional - [Résumé (PDF)](https://cybars69.github.io/resumes/Arsalan_Sheikh-Resume.pdf) - [Sitemap](https://cybars69.github.io/sitemap.xml)