Software development & IT infrastructure for business and the public sector
Today a server in the data centre. Tomorrow an app in the App Store.
Over 25 years of experience and training. From the rack to the iPhone, from one hand.
Pick where it hurts or where you want to go. Everything else follows from the conversation.
From a single server to a highly available cluster: planned, built, documented and operated – with a recovery that has actually been rehearsed.
Software that mirrors your process exactly and adapts to the way you work. Clean, secure, maintainable – with tests and documentation.
Native apps for iPhone, Android, macOS and Windows from one codebase – including signing, store review and updates.
Your own certificate authority, signed e-mails and documents, mTLS and hardening – security you can verify.
Operations with accountability: monitoring, patch management, incident plan – or an honest second opinion on your plans.
A custom-built phone system with announcements like a corporation – “Press 1 for …” – updated through a web interface in seconds. Voice bots answer calls, book appointments into your calendar or survey your customers. The world's first multilingual phone system: callers from +43 and +49 hear German, from +1 English.
The full range: the online business card, the brochure site, the complex e-commerce application. Fast, multilingual, accessible and with clean hosting.
We command and master every programming language – from COBOL and C through Java, C#, Python, Go and Rust to Swift, Kotlin and TypeScript. Understand existing code, modernise it and connect it with the new.
Eight fields, one standard: technology that holds – today and in ten years.
Servers, network, virtualisation, storage and backup – planned as a whole, coordinated down to the last detail.
Clusters, redundant paths, rehearsed failover.
Proxmox, VMware or Kubernetes – sized to fit.
3-2-1 strategy, offsite copy, regular restore tests.
Segmentation, VLANs, firewalls, VPN, zero trust.
Backends, interfaces and automation – built for your workflow, with tests, documentation and a clear operating concept.
TypeScript, Rust, Python – strictly typed, well tested.
ERP, CRM, accounting, mail – your systems talk to each other.
Workflows, reports and routine run on their own.
Claude-based assistants where they truly save time.
iPhone, Android, macOS, Windows and web from a single project – including signing, store review and updates.
Native shell, biometrics, push, share target, deep links.
macOS notarised, Windows signed, Linux packages.
Review guidelines, screenshots, privacy labels.
Automatic updates with signed releases.
Your own certificate authority, signed e-mails and PDFs, mTLS for services and devices – trust on a cryptographic basis.
Root offline, issuing CA online, ACME for internal services.
S/MIME for e-mail, PAdES with timestamp for PDF.
Client certificates, mTLS, least privilege.
Baselines, patch management, audit logs.
Monitoring, patches, incident plan and an honest second opinion – so technology stays reliable.
Metrics, logs, alerts – before anyone notices.
Scheduled, tested, documented.
Runbooks, restart procedures, rehearsed scenarios.
Architecture review, cost control, make-or-buy.
A custom-built phone system with voice menu, voice bots and greetings in over 140 languages – adjusted through a web interface in seconds.
“Press 1 for …” – announcements, forwarding and opening hours like a corporation.
Change announcements, destinations and hours yourself – live, in seconds.
Answer calls, book appointments into your calendar and survey customers – for example how many technicians they need next week.
The world's first multilingual phone system: +43 and +49 hear German, +1 English. You choose language, voice and pitch freely.
Online business card, brochure site or complex shop – designed, built and operated from one source.
One page that makes you findable: contact, services, opening hours.
Several pages, several languages, blog and forms.
Catalogue, cart, payment, shipping, integrations with ERP and accounting.
Fast load times, accessibility, search engines and hosting included.
We command and master every programming language – from mainframe to microcontroller, from legacy system to the newest framework.
COBOL, C, Delphi, Visual Basic, Perl, PHP – understood and maintained.
TypeScript, Rust, Go, Python, Java, C#, Swift, Kotlin.
Modernise legacy systems step by step, while they keep running.
Connect old and new: interfaces, data migration, tests.
Many already run as TestFlight betas on iPhone, iPad and Mac – join in and help shape the first release.
Screenshot annotations – lightweight, native, focused.
Capture a region, add numbered arrows, boxes, text and a magnifier, then save and copy with one click. My first tool – open source and free on every platform.
Copy messy text. Tap once. Get polish back.
Refines copied text with AI – improve, beautify, add emojis – and redacts personal data on the device first. My favourite app.
Your Mac, in its lane.
DNS protection against ads, trackers and known threats for every app: one switch, your own lists, a program guard and a MASQUE tunnel.
A free image editor you can change.
Layers, masks, brushes, retouching and filters – with a plug-in shop and an MCP interface so AI agents can edit images too.
A calculator that tiles into real windows.
Every pad is a real window that snaps flush to the next one. Twenty skins, 8-bit click sounds, more than twenty languages.
Two panes. Keyboard, mouse or touch.
A dual-pane file manager for every platform in the Norton Commander tradition: F5 copy, F6 move, drag and drop, encrypted Matrix Drive and MCP control for AI agents.
A fast, honest task manager.
CPU, memory, GPU, disk, network and processes live – with honest numbers. On Windows with process trees, services and ports; viewers for iPhone, Apple Watch and Apple TV.
Reading, more comfortable than ever.
Reading app for the book by Isabell Frey on every platform and in several languages: read-aloud mode for falling asleep, font size, background and text colour freely adjustable, video animations and an interactive reading experience.
Keeps AI agents moving.
Captures the button to press, including its position on screen; a listener checks every four seconds whether it appears and clicks it. For Cursor today, Codex and further agents next. Open source.
Every stage left its mark on how the work gets done: plan thoroughly, build cleanly, operate honestly.
Started in 1996 with a Windows 95 PC: Intel Pentium 233 MHz MMX, 32 MB RAM, 20 GB hard disk. Then IT technician: assembled computer hardware, set up the first networks and servers.
Web design and HTML programming added. Computer science becomes a passion, and the hardware side stays one.
Windows NT 4, 95, 98, ME, 2000 and XP explored and specialised: servers, domains and clients in everyday business.
Data centres, virtualisation, storage and high availability. Responsibility for systems that run around the clock.
Custom software and web platforms on MySQL and PostgreSQL, first cloud migrations, interfaces between worlds.
macOS, iOS, tvOS and watchOS understood from the ground up, first own apps, plus Windows 7, 8 and 8.1 in support.
iOS and Android, CI/CD, infrastructure as code, Firebase as backend. Security as part of every project.
Pandemic and health events: IT LEASING ONLINE ceases client operations. Start of pure research and development.
Ubuntu, Debian and Arch alongside Windows 10 and 11, macOS and Android: every operating system as a tool in the box.
Among the first on ChatGPT. AI-assisted tools become part of the daily work.
Renamed from IT LEASING ONLINE to IT LEASING OFFLINE: researching and developing fully automated software for businesses in peace.
Kainzmayer Root CA: root offline, issuing CA online. Signed e-mails and documents, verifiable by anyone.
FeatherShot, Beaut1fy, Clay, Calky and more: one codebase, every platform, all the way to the App Store.
AI agents at the highest level build software alongside: Studio, signature infrastructure, website in 24 languages.
Kainzmayer opens again for client projects: from the rack to the App Store, with everything these years have taught.
A selection – anonymised out of discretion.
Complete automation and digitalisation of every process – e-mail, telephony, SMS and AI functions in one portal, with a management system for nine roles. Apps for iOS, macOS, Windows, Android and Huawei.
Consolidation of two server rooms into one highly available data centre with offsite backup and a rehearsed restart.
Custom software connected to POS, accounting and suppliers – replacing three isolated tools and a lot of manual work.
Native app for iOS and Android from one codebase, with offline mode, push and signed PDF reports.
Reading app for every platform in several languages – with read-aloud mode for falling asleep, freely adjustable font size, background and text colour, video animations and interactive elements.
Custom-built phone system with voice menu and voice bot: callers are greeted in their language based on the dialling code, appointments land straight in the calendar, the team changes announcements itself in the web interface.
Every e-mail from Kainzmayer is S/MIME-signed. Every document can be delivered as a signed PDF with a timestamp. The certificates come from an own, published PKI.
S/MIME-signed with a certificate from the Kainzmayer PKI. Apple Mail, Outlook and Thunderbird show the seal; with the root certificate installed it counts as trusted.
Request a signed replyPAdES signature with RFC 3161 timestamp and long-term validation – verifiable ten years from now.
Verify a PDFKainzmayer Root CA G2: root offline, issuing CA online. Certificates for devices, services and documents.
Root certificate & fingerprintsSecurity reports to security@kainzmayer.xyz – details in security.txt per RFC 9116.
security.txt95:EA:0C:CD:52:F1:65:0C:22:C4:50:DE:89:D6:A0:6D:CC:81:53:76:3D:A2:50:9B:41:01:4C:0F:BB:EB:DA:6FDescribe your project in a few lines. You will get a reply – digitally signed.
Your message has arrived – you will hear from me shortly.
Kurt Steven