The builder's path
For: Renters in Berlin can't check before signing whether an advertised rent breaks the rent cap.
“The true creator is necessity, which is the mother of our invention.”
Routes to a solution
Each route is a different kind of journey, with real people and organisations to contact at each step, starting with those in Berlin.
Step 1
Join an incubator or startup mission
They connect you to schemes and officials.
Y Combinator's free course and co-founder matching.
Accelerator for tech nonprofits.
Network of civic tech groups in many countries; find the one near the problem.
Step 2
Win a seed grant
Prove the idea works with a small, funded prototype.
Funds bold ideas in global health and humanitarian work.
Let the people a free tool helps fund its maintainer directly.
Grants for open source that makes the internet better.
Funds open source solutions from emerging economies.
Step 3
Pilot with a public body
A district, city or department tries it with real people.
Network of civic tech groups in many countries; find the one near the problem.
Ideas, sources and tools for this problem, from first interviews to funding.
The official Berlin rent index and online lookup that sets the comparison rent.
Berlin tenants' association that checks rents and takes cases against landlords.
Starter prompt
Built from this problem's brief. Paste it into Claude or any AI assistant.
Help me design and build a first working prototype for this problem in Berlin, Germany. Problem: Renters in Berlin can't check before signing whether an advertised rent breaks the rent cap. Who it hurts: People searching for a flat in Berlin, including newcomers who don't know the local rent rules. The moment it hurts: Seeing a listing, or being handed a lease, with a rent well above what neighbours pay. What people do today: Renters sign because flats are scarce, then some ask a tenant group or the city's rent-check office to compare the rent with the local rent index afterwards. Why it is still unsolved: The check needs the flat's size, age, features and the rent index, plus possible exceptions, so most people never do it before signing. What solved looks like: A renter pastes a listing link or enters the flat's details and gets an estimate of the legal maximum rent under the rent cap, how far the asking rent is above it, and the next steps to reclaim overpaid rent. Where: Berlin, Germany First, list what you would need to learn from the people affected before building, as interview questions. Then propose the simplest version that would help, the screens or messages it needs, and the data it would use. Keep it cheap to run, accessible, and respectful of people's privacy. Flag anything you are unsure about instead of guessing.
Talk to the people who live it before you build.
“The unexamined life is not worth living.”
ὁ δὲ ἀνεξέταστος βίος οὐ βιωτὸς ἀνθρώπῳ
Get a working version in front of people fast.
Using AI is not cheating. Every tool carries the work of the people who made it, and using it well is how knowledge has always moved forward. The thinking, the care for the people who live the problem, and the judgement are still yours.
“The Analytical Engine weaves algebraical patterns just as the Jacquard-loom weaves flowers and leaves.”
Open data that fits this problem.
“You cannot step twice into the same river.”
Tools matched to what this problem needs.
“We are like dwarfs sitting on the shoulders of giants; we see more, and things more distant, not by our own sharp sight but because we are lifted up by their greatness.”
Ship it responsibly, and find help and funding.
“Your right is to the work alone, never to its fruits.”
कर्मण्येवाधिकारस्ते मा फलेषु कदाचन
karmaṇy evādhikāras te mā phaleṣu kadācana
Kit written for this problem from its brief; every link was checked. Links go to each provider's own site. Zetema is not paid for any listing.