IT professional

Owner, IT service for small businesses

IT Service Georg Heiler since January 2017; before that Computer Heiler, from about 1995 to 2015

• IT support, hardware, networks and maintenance contracts for small and very small companies, for more than 30 years.
• My first content management system, for a car dealership in Grünstadt: designed their website together with them and built an Access database for their whole vehicle stock. After adding or updating a car, a single click rebuilt the complete website locally and uploaded it, a static site generator before the term existed. Paid in kind, with a Lancia Thema.
• Built my own business software in VB.NET with SQLite (since 2019, still in daily use): customers, maintenance contracts, invoicing, PDF generation, bank statement import and yearly reports.
• Web applications in PHP with MySQL and PostgreSQL since about 1997, including invoicing and billing tools. Since early 2026 also with AI coding assistants, among other things a relay service for LLM APIs.

Founder and developer, Prefill (prefill.eu)

2026, in development, about 80 percent complete

• Browser extension for Chrome and Firefox that prepares one post for several social networks (X, Bluesky, Threads, Mastodon and W Social, the European network with verified real people as users): text, hashtags, images and image descriptions go into each platform's own composer, and the user publishes with their own click. Nothing is ever posted by accident.
• Write an image description once, and it lands correctly on every platform, shortened to each platform's limit.
• No passwords or session data ever reach the server. Platform selectors ship as signed data (Ed25519), so a change on a platform is fixed in minutes without a new store review.
• TypeScript, Manifest V3, Fastify API with PostgreSQL, payments via Mollie and PayPal, 135 automated tests. Built together with Claude Code.

Career break for health reasons

2015 to 2016

Virtual worlds and 3D, self-directed

Since 2007

• Active in Second Life since February 2007: learned the scripting language LSL and wrote my own interactive objects.
• Since September 2021, run my own OpenSim grid (an open source virtual world server) locally on my own machine, including building, scripting and content. It is connected to the Hypergrid, so its avatars can travel to other OpenSim worlds; it could just as well run fully closed off.
• Developed concepts for using a self-hosted OpenSim grid as a low cost 3D visualisation platform for businesses: walk-through models of buildings, rooms or products that customers can explore together online. Not yet offered commercially; open to projects.
• Since about 2018, 3D modelling in Blender, self-taught with video tutorials; by now well beyond the basics.

Linux server administration

Since the mid or late 1990s, on and off

• Built and ran Linux servers with the full web stack, including PHP and a database.
• Maintained a Magento online shop installation and set up a PrestaShop online shop for another client.
• Defended it overnight against a DDoS attack of about 10,000 requests per minute.

Developer and vendor, billiard hall time billing software

GORKO Software, with a partner, 1991 to the late 1990s; in use until about 2009

• Wrote a time based billing system for billiard tables in Visual Basic for Windows 3.x and sold it to billiard halls worldwide.
• Built it with a partner: he contributed ideas, sketches and some of the graphics, such as the on-screen keyboard keys; I built the user interface and wrote the program.
• Installations ran for nearly 20 years, until 64 bit Windows 7 ended support for 16 bit programs.
• Tested it for the year 2000 changeover; it ran through New Year 2000 without problems.
• For the euro changeover, with the source code already lost, patched the compiled program directly in the binary in the region, changing the currency from DM to €, and sent the patched program to the few remaining installations.

Reverse engineering, self-directed

First attempts in the mid 1980s; seriously from 1993

• First attempts on the Schneider CPC 464, with a disassembler loaded from cassette.
• Analysed Windows programs at assembly level with the SoftICE kernel debugger, for example to understand and modify game save files.
• Learned to read basic x86 assembly in a debugger and how software protection worked in practice at the time.

Teacher of yoga, tai chi and kung fu

From about 1988, alongside my other work, for more than twenty years

• Taught classes in studios and at an adult education centre (VHS Pirmasens), at times up to nine hours a day.
• Dan grade in kung fu, May 1991.

Owner, Game-Shop (software rental)

About 1989 to 1993

• Wrote a point of sale system in dBase: barcode scanning for customer cards and products, a customer database and receipts on a dot matrix printer. Designed and printed the barcodes for the customer cards myself, and for any game whose own barcode was unusable.
• Closed it when a change in German law banned the rental of software.

Owner, Groovesoft (software mail order)

1987 to about 1989

• Sold software by mail order. Closed it when the orders became too many to pack and ship alone every evening.

Family real estate business

1982 to 1989

• At 18, took over the day to day management of the family's real estate and sold the portfolio over seven years in tough negotiations with banks and buyers.
• Managed around 150 residential units, including service charge statements and yearly economic calculations for a property leased to the German federal government.