HomeSenior Software Engineer building ads infrastructure and distributed systems at Bolt Technology.https://rayeen.in/Designing a Top-K System with Sub-Minute Latencyhttps://rayeen.in/blog/designing-top-k-system-sub-minute-latency/https://rayeen.in/blog/designing-top-k-system-sub-minute-latency/A deep dive into designing a real-time Top-K ranking system — Kafka ingestion, Flink sliding windows, Redis sorted sets, failure handling, and scaling strategies.Tue, 10 Mar 2026 00:00:00 GMTDesigning a Real-Time Ad Click Aggregatorhttps://rayeen.in/blog/designing-real-time-ad-click-aggregator/https://rayeen.in/blog/designing-real-time-ad-click-aggregator/A deep dive into designing a real-time ad click aggregation system using Flink, Kafka/Kinesis — covering watermarks, deduplication, Lambda vs Kappa architecture, and interview framing.Mon, 09 Mar 2026 00:00:00 GMTDesigning a Planet-Scale Auction Systemhttps://rayeen.in/blog/designing-planet-scale-auction-system/https://rayeen.in/blog/designing-planet-scale-auction-system/An opinionated deep dive into designing a high-scale auction system: consistency, concurrency control, fraud prevention, global scaling, and trade-offs.Mon, 09 Mar 2026 00:00:00 GMTFrom Domain to Production — Setting Up GitHub Actions for Auto Deploymenthttps://rayeen.in/blog/github-actions-auto-deployment/https://rayeen.in/blog/github-actions-auto-deployment/Part 2 of a 2-part series: eliminate manual SSH deployments with GitHub Actions CI/CD — secure SSH keys, deploy user setup, and automated nginx reloads.Sun, 08 Mar 2026 00:00:00 GMTSelf-Hosting n8n on a VPS with Docker & Nginx Reverse Proxyhttps://rayeen.in/blog/n8n-subdomain-architecture/https://rayeen.in/blog/n8n-subdomain-architecture/How I added n8n as a subdomain service on my VPS — Docker setup, Nginx reverse proxy, SSL expansion, and why you should never expose Docker ports publicly.Sun, 08 Mar 2026 00:00:00 GMTFrom Domain to Production — Bootstrapping My Personal Website on a VPShttps://rayeen.in/blog/bootstrapping-personal-website-on-vps/https://rayeen.in/blog/bootstrapping-personal-website-on-vps/Part 1 of a 2-part series: every step from buying a domain to serving your website securely over HTTPS on a VPS — DNS, Nginx, firewall, and Let's Encrypt.Sat, 07 Mar 2026 00:00:00 GMTrayeen.inhttps://rayeen.in/projects/project-1/https://rayeen.in/projects/project-1/My personal portfolio and blog, built with Astro, Tailwind, and TypeScript.Fri, 07 Mar 2025 00:00:00 GMT