Deven Aggarwal

Senior Full-Stack Developer · WordPress Multi-Site Management Platform

SEO Brand • Freelance

Jan 2026 - Apr 2026 • 3 mos

The agency managed 30+ client websites on WordPress, each with its own Yoast SEO settings, schema markup, theme version, and content cadence. Updating a single site-wide policy — rolling out new FAQ schema across all clients, pushing a Yoast configuration change — meant logging into 30 separate WordPress dashboards. A typical rollout cost the SEO team 4–6 hours per change and introduced human-error inconsistencies that quietly broke search performance on individual sites. I built them a centralized control plane: a Next.js application that connects to each client site via the WordPress REST API, displays unified configuration across the entire portfolio, and lets the team push changes site-by-site or in bulk with one click. The interesting technical challenge wasn't the dashboard itself — it was authentication and rate-limiting. WordPress REST API auth typically uses application passwords, but rotating 30 sets of credentials through environment variables wasn't workable for a 6-person team. I built a credential vault backed by Supabase with field-level encryption, plus a queue-based bulk-update system using BullMQ that respects per-site rate limits (some clients ran on shared hosting that throttled aggressively). Updates that would have blown out a single-request approach now stage cleanly across 4–6 minutes per 30-site rollout. The surprise was hosting heterogeneity. Eight of the 30 sites had Wordfence or iThemes Security plugins blocking the REST API by default. Rather than have the team disable security per site, I built a detection layer that flagged sites with blocked endpoints and produced a one-time per-client setup checklist they could send to the host to whitelist our origin. That single check eliminated 90% of failed deployments. The agency now ships site-wide SEO policy changes in under 5 minutes of human time. Per-change error rate dropped to near zero. The system has been running for three months across all 30 sites.

Browser Automation & Competitor Intelligence

Upwork • Part-time

Dec 2025 - Mar 2026 • 3 mos

The client — a mid-sized Indian D2C electronics brand — needed to monitor competitor pricing and inventory across 12 sites every 4 hours: Amazon, Flipkart, and 10 niche category retailers. They had been tracking this manually, with 2 team members spending 2–3 hours per day. Missed price moves cost them margin; competitors ran 24-hour flash sales, but the team only spotted them the next day. I built an automated monitoring system using Playwright on a headless Chromium fleet (AWS EC2 spot instances). It tracks 240 SKUs across 12 source sites, normalizes pricing and stock status into a unified PostgreSQL schema, and pushes Slack alerts for price drops and out-of-stock events. The interesting technical challenge was anti-bot defenses. Two sources used Cloudflare's bot challenge; two more used custom JavaScript fingerprinting that flagged headless browsers within minutes. Rather than chase a cat-and-mouse, I built rotating residential proxy support via Bright Data and configured Playwright with realistic fingerprints — proper user agents, screen resolutions, and timing jitter between actions. Page-load patterns now mirror human browsing, which kept us inside source rate limits. The surprise was Flipkart: the price for several SKUs only becomes visible after adding to cart — the final price is hidden behind an interaction step. I built a state machine that handles each source's rendering quirks: conditional cart additions for Flipkart, authenticated-then-extract flows for two B2B portals. Each source's logic is isolated in its own adapter, so adding the 13th source becomes a 30-minute task rather than a refactor. The brand now sees price movements within 4 hours, runs automated price-match adjustments on its bestseller catalog, and has reclaimed 8–12 hours per week of manual tracking. Margin protection paid the build back in month two. Stack: Playwright, Node.js, PostgreSQL, AWS EC2 spot instances, Bright Data residential proxies, Slack API, Vercel.

WordPress subdomain platform

Freelancer.com • Freelance

Apr 2025 - Nov 2025 • 7 mos

The client ran a programmatic SEO operation that required thousands of independent subdomains, each ranking independently. Their existing setup installed a fresh WordPress on every subdomain: separate database, separate plugins, separate update cadence, separate backups. Scaling past 30 sites meant ops costs were eating up the SEO upside; updating the shared plugin across 30 installs took an afternoon. I built a different architecture: one centralized WordPress where each WordPress category maps to its own subdomain. Adding a subdomain means adding a category in the WP admin. The team publishes a post under that category, and it appears live on the matching subdomain within seconds. One backend, thousands of front-end sites — no separate install, database, or plugin update cadence per site. The technical challenge was making each subdomain appear to Google as a standalone site. The system intercepts the Host header at Nginx and routes the subdomain slug to WordPress. A custom plugin hooks pre_get_posts, home_url, and parse_request to set the active category as the subdomain's site root — posts render at subdomain/post-slug, not example.com/category/subdomain/post-slug. Each subdomain ships its own filtered sitemap, robots.txt file, Organization + Websiteschema, and canonical URLs. Google treats every subdomain as a separate site — confirmed across hundreds of live subdomains. The surprise was an internal lin bleed. WordPress's default related-posts and category widgets linked across subdomains, polluting each site's link graph with off-subdomain URLs. I built a context-aware link filter that rewrites all internal links to stay within the active subdomain's category — so each link graph is self-contained, looking exactly like a standalone site to crawlers. The platform now hosts subdomains in the low thousands, lets the team spin up a new ranking-eligible site by creating a single WordPress category, and consolidates installs into a centralized backend.