Senior Laravel & PHP Developer | AI Integration, n8n, Payment APIs | Germany-based
Senior Laravel/PHP Developer & AI Integration Expert
I help businesses fix complex bugs, integrate payment systems, automate workflows, and build AI-powered applications. I am based in Cologne, Germany and operate TechnoPC GmbH (registered IT company, HRB 114519).
CORE EXPERTISE
Payment Integration and Debugging
- Mollie, Stripe, PayPal, SOFORT - webhook debugging and IPN handling
- Race conditions, retry logic, idempotency
- WooCommerce, CS-Cart, Laravel checkout flows
Full-Stack Development
- Laravel 12 + PHP 8.3 (15+ years experience)
- RESTful APIs and webhook integrations
- Multi-tenant SaaS architecture
- MySQL / MariaDB optimization
E-Commerce and Bug Fixing
- WordPress / WooCommerce troubleshooting
- CS-Cart custom add-ons, themes, performance tuning
- Payment gateway debugging
- Cron jobs and server-side automation
AI Integration
- Anthropic Claude API (production deployments)
- OpenAI GPT-4, embeddings, prompt engineering
- Voice AI (Retell AI, Vapi)
- Multi-language NLP (DE, EN, TR, FR, IT, ES)
Workflow Automation
- n8n complex workflows (production-scale)
- Telegram, WhatsApp, Instagram bot integrations
- Custom automation pipelines
Infrastructure and DevOps
- Linux/Ubuntu, Hetzner, Oracle Cloud
- Webmin, Virtualmin, Apache, Nginx
- Docker, Cloudflare, server hardening
WHY WORK WITH ME
- Backed by registered German GmbH (TechnoPC GmbH) for professional VAT invoicing
- EU/GDPR-compliant by default
- CET timezone with same-day response during EU business hours
- Direct communication, no middlemen, no outsourcing
- 15+ years hands-on full-stack development
- Production AI deployments serving real customers
LANGUAGES
English (Fluent), German (Business level), Turkish (Native)
I look forward to working on your project.
Work Terms
AVAILABILITY
Monday to Friday, 09:00 to 18:00 CET (Central European Time, Cologne, Germany)
Same-day response during business hours
Limited availability on weekends for urgent issues
COMMUNICATION
- All communication through Guru platform messaging
- Voice and video calls available via Google Meet or Zoom when needed
- I respond to messages within 2-4 hours during business days
PROCESS FOR NEW PROJECTS
1. Initial review of your requirements (always free, no obligation)
2. Written quote with clear scope and estimated timeline
3. Milestone-based work for projects over $300
4. Daily progress updates for ongoing engagements
5. Source code, documentation, and handover at project completion
PAYMENT TERMS
- Hourly projects: Time tracked through Guru WorkRoom or shared timesheet
- Fixed-price projects: 30% deposit / 40% mid-milestone / 30% on delivery
- All payments through Guru SafePay (escrow protection for both parties)
- Professional VAT invoicing available through TechnoPC GmbH for EU clients
REVISIONS AND WARRANTY
- Bug fixes during the project: included
- 14 days post-delivery warranty for any issues directly related to delivered work
- Out-of-scope changes: separate quote provided
WHAT I PROVIDE
- Clean, documented, production-ready code
- Standards-compliant solutions (PSR for PHP, n8n best practices)
- Brief written summary of changes made
- Recommendations for future improvements when relevant
WHAT I NEED FROM YOU
- Clear description of the issue or requirement
- Working environment for the relevant systems (staging preferred for live sites
- Timely feedback on questions or proposed solutions
- For payment integration debugging: test credentials and sample failed transactions
CONFIDENTIALITY
I treat all client information, code, and credentials as strictly confidential. NDAs available upon request. I do not subcontract work or share project details outside the engagement.
LANGUAGES
English (Fluent), German (Business level), Turkish (Native)