Proof of work

Things I built, and the kind of work I do.

My client work is confidential, so I don't name clients. My own products are public: they run in production, you can open them, and they show what I care about. Email security, compliance that can be proven, and software that removes manual work.

Email security · SaaS or self-hosted · live

DMARC Geeks

DMARC only protects a domain when it reaches p=reject, and getting there means knowing every service that sends mail in your name. DMARC Geeks collects the aggregate reports, parses them and shows which senders still fail SPF or DKIM, across many domains and tenants. It is built for IT teams, MSPs and agencies.

DMARC report analytics with multi-tenant support
Public DNS check: MX, SPF, DKIM, DMARC, MTA-STS, TLS-RPT, BIMI
Mail tester: send a message, get a score with SPF, DKIM, DMARC, blacklist and spam analysis
Microsoft 365 threat test: harmless EICAR and GTUBE test strings show what Defender and EOP deliver, junk or quarantine

dmarc-geeks.ch DNS check Mail tester Threat test

DMARC Geeks dashboard with daily pass and fail volumes across several domains — Dashboard: DMARC pass and fail per day (demo data).

DMARC Geeks mail tester result page — Mail tester: score and authentication results for a test message.

DMARC Geeks Microsoft 365 threat test form with the list of test messages — Threat test: which Defender policy catches which test mail.

Own product · accessibility · AI · live

DokAudit

Public bodies and companies publish thousands of PDFs that have to work with a screen reader. DokAudit makes PDFs accessible according to PDF/UA, WCAG and EN 301 549, and proves it: it checks like veraPDF and PAC, repairs what can be repaired automatically, and documents the result. The goal for every document is that both checkers are green.

Automatic repair of tagging, headings, lists and tables, fonts (embedding, ToUnicode, widths), form field tooltips, links and artifacts; colour contrast optional
A local layout model (Docling/Heron) recognises structure: correct structure per character rose from 63.1% to 95.5%
An LLM only for uncertain pages, cross-checked against the page image, within a cost limit per page
Own worker fleet with a GPU, about 1.8 seconds per page; learned rules go global only after a cross-check
Example: a 1,181-page municipal budget went from 241,880 to 31 veraPDF errors in one run, then fully green

dokaudit.com Public PDF scan The case and architecture

DokAudit page How DokAudit works: rules first, AI only where needed, every change re-measured — How the checks and repairs work.

DokAudit public scan: enter a website address and DokAudit checks the linked PDFs — Public scan, no login (German).

Hosting platform · AI · live

VibeBoxes

More and more people build web apps by describing them to an AI. The hard part comes afterwards: hosting, HTTPS, updates, and getting back to yesterday's version when something breaks. VibeBoxes gives every app its own container with versioning and one-click rollback, and offers audits of AI-written code before it goes live.

One isolated container per app, automatic HTTPS
Every change is a saved version, rollback with one click
An MCP interface so the AI can publish directly
Vibe-code audits: security and quality review of AI-built apps
Hosting in Switzerland and the EU

vibeboxes.ch

Business software · on-premises or hosted · demo

Kursbox

Booking and administration software for university sports programmes: course catalogue, online booking, payments, facilities, instructors with fee calculation, communication and statistics in one system. Built to survive the rush when registration opens: every booking runs in a database transaction, so a course can never be overbooked.

Node.js and PostgreSQL, server-rendered, runs on-premises with Docker Compose
Single sign-on via SAML 2.0 / Shibboleth
Roles and permissions, audit log, data protection functions
Documented REST API (OpenAPI), iCal feeds, CSV and Excel import/export

Open the demo

Kursbox statistics with utilisation per sport and combinable filters — Statistics with combinable filters.

Kursbox facility booking plan with detection of double bookings — Facility plan with double-booking detection.

Kursbox booking on a phone: choosing the payment method — Booking on a phone.

Client work, anonymised

Microsoft 365 projects I have delivered

For clients in Germany and Switzerland, in sectors such as occupational pensions, finance and wealth management, fiduciary services, industry, education, hospitality, healthcare and travel.

Problem, build and proof for each kind of work

Mail

Hybrid mail routing fixed in phases
MX cutover readiness and cutover
Exchange Server decommissioning
SMTP relay replaced by Microsoft Graph
SPF, DKIM and DMARC to p=reject

Security & identity

Conditional Access rollout in five phases
CIS benchmark gaps closed
Evidence kits for regulated financial clients
TLS hardening
SharePoint permission audits

Workplace

Intune and Windows Autopilot
Profile migration from local AD to Entra ID
File server to SharePoint, OneDrive rollouts
Remote Desktop Services replaced
Secure Boot certificate updates (2023 CA)

Want to see something in detail?

I am happy to walk you through any of these products, or through how I would approach your environment.

hello@lappenbusch.com CV