How I Turned A Retirement Countdown Idea Into An AI Coding Project

🔍 Read the full analysis: How I Turned A Retirement Countdown Idea Into An AI Coding Project on ThorstenMeyerAI.com

Thorsten Meyer says he built and published a free German partial-retirement countdown app in five days with help from an AI coding agent, turning an idea for a one-minute film into a site with a daily working-day count, a narrator-led film and 19 3D games. Meyer says the agent, Claude Opus 5.5, contributed to all 24 commits, while he set the direction, made decisions and approved releases.

The project began on Monday, September 28, 2026, when Meyer asked the agent for a short animated film about the two phases of German Altersteilzeit in the block model. Under that arrangement, a person works as usual during an active phase and is then released from work for an equal period; a 4:4 model, for example, pairs four working years with four years off. By Friday, October 2, Meyer says the result was a public website rather than just a film.

Users enter the start date of either phase and choose a model from 1:1 to 5:5. The site calculates the other date and counts working days, using weekdays, public holidays for the selected German state and leave entered by the user. Its daily view includes a progress ring, a saying and upcoming milestones. Other tools include a bridge-day finder, calendar exports, a printable countdown and a team countdown.

The site also includes a narrated film about the user’s two phases and 19 games that use time as their structure. Meyer describes seven languages, five German dialects, badges, four difficulty levels and weather that follows the real calendar. He says the project used about 18,000 lines of JavaScript and Python, 15 test scripts and 1,224 voice clips. These figures and the account of the build come from Meyer’s October 13 project report.

What the Build Says About AI Coding

The project offers a specific example of what an AI coding agent can contribute to a small software release: not only code, but also tests, translation work, audio production and deployment. Meyer’s account describes a rapid path from a narrowly defined creative request to a site with multiple tools and game modes. It is a report of one project, not evidence that every similarly sized app can be made in five days or with the same results.

Meyer’s description also makes the human role visible. He says he chose the concept and tone, decided how the film should feel, selected voices and dialects, and approved releases. Those choices shaped the product beyond its technical functions. For readers considering AI-assisted development, the account points to both the speed of delegated production work and the continuing need for a person to define the goal and judge the output.

The app’s subject is practical as well as personal: people in an Altersteilzeit block model may want to know how many working days remain, rather than simply how many calendar days. By factoring in state holidays and entered leave, the countdown is designed around a user’s work schedule. Meyer says calculations happen in the browser and that the app has no accounts, cookies or tracking.

From Film Request to Countdown Site

Altersteilzeit is a German partial-retirement arrangement. In the block model described by Meyer, the active phase comes first and is followed by an equally long passive phase. The app is built for users who want to track that sequence; it is not presented as a tool for determining eligibility or explaining the legal terms of an individual arrangement.

Meyer’s account gives a short development timeline. On the first day, he says, the agent produced the film and worked on leave calculations, date entry and early 3D game prototypes. The daily view, additional games and language support followed, alongside a reported fix for a mobile scrolling problem. A narrator and sound effects were added on day four, and Meyer approved the release on day five before adding five German dialects as full language options.

The stated workflow was repeated across tasks: Meyer described a feature, the agent returned a plan, built and tested it, recorded its work and deployed it. For larger tasks, Meyer says, the agent divided work among parallel sub-agents, including translators assigned to dialects. His report says those outputs were then checked. That process matters when interpreting the reported pace: the project involved several rounds of direction and review, not a single prompt that generated a finished site.

„The interesting part is not how much an AI agent can build, but what was still left for me to do.“

— Thorsten Meyer, describing the project

What the Project Report Does Not Establish

The development details are based on Meyer’s own account, published on his website. The source material does not include an independent technical review, usage figures, user feedback or a separate assessment of the app’s calculations, accessibility or performance. The reported line counts, clip totals, commit authorship and five-day schedule have not been independently verified here.

It is also unclear how the site handles unusual work schedules or arrangements that differ from the standard weekday pattern described in the report. Meyer says working-day calculations account for a German federal state’s public holidays and user-entered leave, but the report does not specify the full range of supported cases. It gives no information about ongoing maintenance, operating costs or whether the app’s features will change.

How the App Will Be Maintained

Meyer’s report establishes that he approved the site after the five-day build and added dialect options on the final day. It does not announce a further release date, a roadmap or a planned follow-up project. The next practical questions are whether the public app remains available, how its calculations and browser compatibility will be maintained, and whether Meyer will publish updates based on user feedback. No schedule for those developments was provided.

Key Questions

What is the Altersteilzeit countdown app?

It is a free web app described by Thorsten Meyer. Users enter the start date of an active or passive phase and select a model; the app calculates dates and counts working days, including relevant public holidays and entered leave.

How long did the project take?

Meyer says development ran from September 28 to October 2, 2026, a five-day period. That timeline comes from his project report and has not been independently verified.

What did the AI coding agent do?

Meyer says Claude Opus 5.5 helped with engineering, testing, translations, voice clips, sound effects and deployment. He says he set the direction, made product decisions and approved releases.

Does the app collect personal data?

Meyer says the app has no accounts, cookies or tracking and calculates dates in the browser. He also says shared dates are placed after the “#” in a web address, which browsers do not send to the server. Those privacy details are claims in his report, not an independent audit.

What is not yet known about the project?

The source report does not provide independent testing, user numbers, user feedback or a maintenance plan. It also does not detail support for work schedules outside the weekday-based calculation it describes.

Source: ThorstenMeyerAI.com