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GerMailBox
germailbox.deA privacy-first email service hosted in Germany — built for users who want full control over their inbox, with strong anti-spam and zero third-party tracking. End-to-end engineered by FrenzelTech.
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Real systems, real results.
A look at what I've built across AI, automation, voice and e-commerce — each with starting point, solution and measurable result. Customers anonymised, numbers real.
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Real platforms I designed, built and operate. Click any card to open the live site.
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Spendings
spendings.chA modern personal & business expense tracking platform. Categorize, analyze and forecast your spendings with a clean Angular UI and a robust API backend — EU-hosted and privacy-respecting.
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BuyThis Demo
demo.buythis.chAn on-premise modern e-commerce platform — fully owned, no SaaS lock-in, customizable storefront, Stripe + SEPA checkout, multi-store ready. Deploy and run on your own infrastructure.
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E-Commerce Anonymised reference
Self-hosted shop platform
- Starting point
- A SaaS shop with transaction fees, little control over data and hardly any room for customisation. Every extension depended on the vendor.
- Solution
- Replaced by a fully owned multi-store platform built with Angular, Node.js and PostgreSQL, Stripe checkout, deployed on-premise.
- Result
- Checkout 4.2× faster, operating costs down 68%, 99.99% uptime since go-live.
4.2×Faster checkout
−68%Lower costs
99.99%Uptime
AI Agent Anonymised reference
Autonomous research agent
- Starting point
- Prospects were researched and contacted by hand, and CRM upkeep regularly fell behind.
- Solution
- A LangGraph agent with OpenAI researches prospects, writes personalised outreach and updates the CRM via MCP — grounded on internal data through pgvector.
- Result
- Runs around the clock, 92% reply rate, roughly 40 hours of manual work saved per month.
24/7Always-on
92%Reply rate
−40hManual work saved / mo
Voice AI Anonymised reference
Inbound voice support
- Starting point
- Tier-1 calls tied up the team, and calls outside office hours went unanswered.
- Solution
- A natural-sounding voice agent built with Vapi, ElevenLabs and Twilio handles tier-1 support, qualifies callers and hands over to humans when needed; n8n does the follow-up work.
- Result
- Response latency under 800 ms, over 12,000 calls per month, 7× more capacity without extra staff.
<800msLatency
12k+Calls handled / mo
7×More capacity
Workflow Anonymised reference
n8n orchestration platform
- Starting point
- More than 180 manual processes spread across tools, spreadsheets and inboxes — with no record of who did what and when.
- Solution
- Migrated to a self-hosted n8n platform with monitoring, retries and audit logging; Temporal for long-running flows, REST and webhooks as interfaces.
- Result
- 180+ automations live, 85% fewer manual hours, delivered in three weeks.
180+Automations live
−85%Manual hours cut
3 wkDelivery time
AI Video Anonymised reference
Automated video factory
- Starting point
- Marketing videos were produced separately per language — expensive, slow and hard to keep consistent.
- Solution
- A pipeline turns content briefs into finished videos: HeyGen avatars, Runway B-roll, OpenAI scripts and voice-overs, FFmpeg rendering with localised subtitles.
- Result
- 50× faster output, over 500 videos per month in six languages.
50×Faster output
500+Videos / month
6 langLanguages
MCP Anonymised reference
Internal MCP platform
- Starting point
- Internal tools and data were out of reach for AI assistants; staff copied information into the chat by hand.
- Solution
- A suite of custom MCP servers in TypeScript exposes tools and data to Claude and ChatGPT — Docker-deployed, secured with OAuth2, every call auditable.
- Result
- 15+ MCP tools in use, P95 latency under 50 ms, SOC2-aligned security posture.
15+MCP tools
<50msP95 latency
SOC2Security posture