db123 — who brings stability

The Full-stack Developer who is a DevOps too! has had experiences and is willing to learn.

An Engineer

DevOps engineer with 7 months of production experience owning the full infrastructure of a hotel booking platform (yejayekhoob.com). Built CI/CD pipelines from scratch, Docker images compiled from source, a Go-based auth proxy and DNS failover system, and a Redis caching layer with SQL-aware invalidation — all while managing the sole technical responsibility for the company. Daily Linux user (Arch, 2+ years). Knows system design — can design durable, distributed systems. Comfortable across the entire stack: infrastructure, backend, and frontend.

Skills

HTML & CSS

  • Semantic HTML5
  • BEM naming methodology
  • Flexbox & Grid
  • TailwindCSS

JavaScript & TypeScript

  • DOM & Fetch API
  • Vue.js & Nuxt.js (learning)
  • Async & Event loop

PHP

  • Version migrations
  • Zero-dependency (no framework)
  • Custom .env implementation
  • OOP & Type safety

SQL

  • MariaDB administration
  • Query optimization
  • SQL-aware cache invalidation

Markdown & Mermaid & LaTeX

  • Technical docs (EN & FA)
  • Mermaid diagrams
  • LaTeX maths

BASH & BATCH

  • System administration
  • Shell scripting (cron & rsync)
  • systemd service management
  • Backup automation

GoLang

  • HTTP servers & middleware
  • RESTful & Stateless APIs
  • Concurrency & goroutines
  • Zero-dependency tooling

DevOps / Full-Stack Developer

Yejayekhoob.com — Oct 2025 – Jun 2026 — 7 months

Sole technical lead for a Persian hotel/tour booking platform. Infrastructure, CI/CD, backend, security, and reliability across two data centers (Iran & Finland).

PHP 5.6 → 8.5 Migration

Led migration of a messy legacy PHP codebase across three all-nighters, resolving breaking changes with zero production downtime. Rewrote .env loading from scratch in pure PHP — zero Composer deps, no framework lock-in.

Self-Hosted CI/CD Pipeline

Built complete CI/CD on Gitea Actions with self-hosted runners — sub-second deployments for a pure PHP stack. Multi-job workflows: file sync (rsync) + database sync (mysqldump) between Iran and Finland for disaster recovery. Automated database backups (2x daily, rotation of last 4, ntfy push). Generated system cron configs from JSON definition via CI.

Redis Caching Layer with Intelligent Invalidation

SQL-aware cache that parses queries via regex to detect table changes (INSERT/UPDATE/DELETE) and invalidates only affected keys. Fallback logic — site works transparently if Redis goes down. ~50% of the site uses this cache with configurable TTL per function. Singleton pattern, lazy connection, SHA1-based key generation.

Go Auth Proxy for Nginx

Lightweight HTTP auth proxy integrating with Nginx via auth_request — Alpine container, SQLite backend (WAL mode), API key management (env-injected). IP whitelisting with permanent entries (IP/CIDR) and TTL-based temporary entries with auto-expiry via background goroutine. Production-hardened Docker: multi-stage, non-root, read-only root FS, dropped capabilities.

DNS Failover System (Go + BIND9)

Health-check daemon that monitors a primary BIND server and automatically swaps zone files (primary ↔ failover) with hysteresis — N consecutive failures before switching. State machine pattern (StatePrimary ↔ StateFailover) with configurable timeouts. Integrates via rndc reload. Runs as systemd. Zero external dependencies (pure Go stdlib).

Dockerized Infrastructure

Full production stack in Docker Compose: PHP 8.4 (FPM), Nginx, MariaDB (3.5 GB RAM limit), Redis (AOF), auth-proxy, Gitea, Next.js panels, phpMyAdmin, Uptime Kuma, Prometheus + Grafana. Custom images compiled from source (Nginx 1.29.3 on Alpine, PHP 8.5 on Alpine with security hardening). Nginx security: TLS 1.2/1.3, HSTS, rate limiting (30 r/s), security headers.

Infrastructure & Automation

Two BIND9 DNS servers (Iran + Finland) with automatic failover synced via Gitea CI/CD. Backup automation script (cron). Authored thorough server migration guide (files, databases, SSL, DNS). Managed Iran-specific mirror workarounds for apt/Alpine to keep builds running under sanctions.

Additionals

Education

  • Computer Engineering student
  • good grades in first semester

Languages

  • Persian — Native
  • English — Fluent (technical & conversational)

Currently Exploring

  • Go RESTful stateless services
  • Microservices & distributed systems

Contact

github.com git.db123.ir db123.ir +98 9010844588 erfan@db123.ir Mashhad, Iran