# Mohammad Shadikur Rahman

> Senior infrastructure architect and full-stack engineer with 14+ years of experience in cloud infrastructure, DevOps, telecommunications, and software engineering.
> Building infrastructure as code at OTTO in Hamburg, Germany. Specializing in AWS CDK, microservices, Linux, and VoIP platforms (FreeSWITCH, OpenSIPS, Teams Direct Routing).

Full stack engineer with 14+ years of experience on IT modernization, system integration, cloud infrastructure, and VoIP platforms.

## Core Pages
- [Homepage / Overview](https://shadikur.com): Developer portfolio, about summary, key metrics, and direct contact options.
- [Work / Case Studies](https://shadikur.com/work.txt): In-depth case studies of cloud infrastructure, telecom automation, and full-stack applications.
- [Experience & Career](https://shadikur.com/experience.txt): 14+ year career history spanning AWS CDK, VoIP platforms, microservices, and IT modernization.
- [Blog](https://shadikur.com/blog.txt): Technical articles and tutorials on cloud architecture, DevOps, telecommunications, and modern web development.
- [Uses / Environment](https://shadikur.com/uses.txt): Hardware, software, tooling, and environment setup.

## Featured & Key Projects
- [FusionPBX automation](https://shadikur.com/work/fusionpbx-automation.txt): A multi-tenant SIP PBX on FreeSWITCH, provisioned and maintained by script rather than by hand. Azure Functions drive tenant creation, backups and health checks. (Stack: FreeSWITCH, PHP, PostgreSQL, Azure Functions)
- [Teams ↔ OpenSIPS SBC](https://shadikur.com/work/teams-opensips-sbc.txt): A custom session border controller bridging Microsoft Teams Direct Routing to on-prem SIP trunks, with RTPProxy handling media. (Stack: OpenSIPS, RTPProxy, Teams)
- [Proxmox installer](https://shadikur.com/work/proxmox-installer.txt): Scripted, repeatable Proxmox VE provisioning on Debian — one command from bare metal to a managed hypervisor. (Stack: Proxmox, Shell, Debian)
- [Creative Expressions](https://shadikur.com/work/creative-expressions.txt): An education platform with authentication, course management and role-based dashboards for instructors and students. (Stack: React, Express, MongoDB, JWT)
- [Robot toy marketplace](https://shadikur.com/work/robot-toy-marketplace.txt): A commerce front end with faceted filtering, seller accounts and a Firebase-backed identity layer. (Stack: React, Node.js, Firebase)

## Professional Experience
- [Software Engineer at OTTO](https://shadikur.com/experience.txt): Dec 2024 — now | Hamburg, hybrid. Key focus: Leading migration of existing infrastructure codebases to AWS CDK — scalability, security and automation as defaults, not afterthoughts. (Tech: AWS CDK, TypeScript, GitLab CI/CD, Microservices, IaC, Security)
- [IT System Engineer at Guidepoint](https://shadikur.com/experience.txt): Nov 2019 — Jun 2024 | Düsseldorf. Key focus: Owned on-site networking and hardware infrastructure end to end: replacement, maintenance, monitoring. (Tech: Azure AD, PowerShell, Microsoft Teams, OpenSIPS, Avaya, Windows Server, Linux)
- [Full Stack Engineer at count7](https://shadikur.com/experience.txt): Feb 2015 — Apr 2019 | London. Key focus: Installed and configured 200+ FreePBX (Asterisk) and FusionPBX (FreeSWITCH) systems, with custom modules per customer. (Tech: Asterisk, FreeSWITCH, PHP, MySQL, JavaScript, Cisco, MikroTik, VoIP)
- [QA Engineer at SBSystem UK](https://shadikur.com/experience.txt): Dec 2010 — Oct 2013 | London. Key focus: Wrote and ran Selenium WebDriver suites against Java products, from functional cases through performance. (Tech: Selenium, Java, Docker, Jenkins, Jira, Test Automation)

## Blog Articles
- No published blog posts currently.

## Technical Skills
- **Cloud & infrastructure**: AWS CDK, Azure, Docker, Jenkins, GitLab CI, Terraform-style IaC, NGINX, Linux
- **Frontend**: React, Next.js, TypeScript, JavaScript, Tailwind, HTML/CSS
- **Backend & data**: Node.js, Express, PHP, Java, Python, PostgreSQL, MongoDB, MySQL, Redis
- **Telecom**: FreeSWITCH, FusionPBX, Asterisk, OpenSIPS, SIP, RTPProxy, Teams Direct Routing
- **Practice**: System integration, Automation, Documentation, Mentoring, Agile delivery

## Detailed Context for LLMs
- [Full Text Context](https://shadikur.com/llms-full.txt): Complete expanded document containing full case study write-ups, detailed career history, education, and full article texts for deep AI processing.

## Contact & Links
- **Email**: hello@shadikur.com
- **Location**: Hamburg, Germany
- **GitHub**: https://github.com/shadikur
- **LinkedIn**: https://www.linkedin.com/in/shadikur/
- **Twitter / X**: https://twitter.com/Shadikur