In the beginning ...
Imagine you belong to a car-sharing community: you have multiple users, multiple cars, different tariff models (per minute, per km, different rates for long-distance, free minutes etc.), you need to track all trips, compute what every user owes, send invoices or statements, and you want to avoid manual work all over the place. Doing this by hand means lots of spreadsheets, possibility of errors, disagreements, wasted hours, and frankly, math fatigue (yes, even nerds get tired of balancing columns at midnight).
Originally, in Auersthal (Austria), when "e-GO" the electric car-sharing project started, there were about 25 users. Counting everyone's kilometers, times, figuring out what they owe: manual invoicing was slow, error prone, and as the number of users grew, it got out of hand. The cost—in time, in mistakes—became too high.
Autobill was born
Autobill.at automates all that. It gives car-sharing groups (municipalities, associations, companies) a tool to:
- Define any tariff model: time-based, distance-based, membership fees, free minutes, long-trip surcharges, etc.
- Track multiple vehicles and users / companies in the fleet.
- Import trip / usage data (e.g., periodically from data sources like Caruso), integrate user and vehicle metadata.
- Automatically compute each user’s charges per month, send invoices/statements via email, generate SEPA files for payments, handle credits or debits.
- Provide dashboards and reports: kilometers driven, rides per user, earnings vs cost, usage by time periods.
- Exports, filtering, manual corrections or imports when needed (for example, for retroactive data).
In short: Autobill converts the messy, repetitive, error-prone parts of billing into reliable, maintainable automation. That means less administrative overhead, fewer disputes, more transparency. Instead of someone staying up late trying to reconcile trip logs with invoices, Autobill just does it.
Business model
Autobill operates on a subscription / service-fee basis geared toward car-sharing fleets:
- There is a monthly fee per car: the first car in a fleet has a baseline rate, and each additional car adds a smaller incremental cost.
- There’s a free trial month so new groups can test whether it fits without commitment.
- Pricing and tiers are designed so that small fleets can afford it, and larger ones scale in cost more gently (so costs don’t explode just because you have many cars).
- Extra services, like custom tariff models, special data exports or integrations, or bespoke invoice designs (custom logo, VAT / tax formatting) add value (some included, some “premium”).
The value proposition is strong: time saved, reduced errors, more predictable finances. So even though Autobill charges, the savings (in labor, in mistakes, in clarity) more than pay for itself. For many clients, it's cheaper than someone doing manual billing for several hours every month (plus the headaches).
Technology behind it
Autobill is built with tools and architecture chosen for reliability, maintainability, and scale. Key technical details:
- Backend framework: Ruby on Rails. Over the years the code evolved, been refactored and upgraded so that the app stays modern, secure, and fast.
- Database: PostgreSQL for transactional data: users, trips, vehicles, invoices, tariffs. Relational model works very well for this domain (joins, aggregations, filtering).
- Hosting / Infrastructure: Runs on Linux servers (at the moment Hetzner). Uses dependable techniques for deployment (automated, containerization or process-management tooling). Previously parts were on Heroku, then Dokku on DigitalOcean, now onto more dedicated infrastructure for better performance and cost control.
- Background jobs / queues: Periodic imports of trip data, generating invoices or SEPA files, running monthly reports — a lot is happening in background (queued, retried, asynchronous) so the user interface stays snappy. Jobs are based on solid queue.
- Synchronization: Data from external car-sharing systems (e.g. Caruso) are imported on a schedule to keep trip data up-to-date. If a ride ends, it will show up in Autobill soon after, without manual data entry.
- Exports / Reports: CSV / Excel exports, filtered views, ability to generate PDFs or emails per user with all charges and ride history. Also statistics: km driven per day / month, usage over time, revenue.
- Invoice / Billing logic: Supports complex tariff models: combinations of fixed / variable fees, free minutes, long distances, time vs. distance billing, etc. Also supports membership fees and distinguishing between “member” participants vs casual usage, or special adjustments.
- Design / Frontend basics: UI is clean, functional, focused on clarity: dashboards, tables, filtering, exporting. Not super flashy, but usable, reliable, readable. (Yes, I have a soft spot for Bootstrap or similar, but I promise I don’t judge a tool by its frontend shine, more by whether it makes billing correct.)
- Reliability & Maintenance: Regular updates for security, Rails / Ruby version upgrades, database tuning. Logging, monitoring, backups. Handling error cases: what if import fails, what if data is missing, how to correct manual data, etc.
- Scalability concerns tackled: As more communities adopt Autobill, usage data grows. Keeping queries performant, caching where needed, indexing database properly, ensuring reports don’t grind the system, etc. Also being careful with external API / import delays so that stale data isn’t causing incorrect invoices.
Why it’s fun
- I love the idea that something as “boring” as invoicing or billing can be beautifully crafted. It’s like making sure the gears in a nice clock all mesh, unseen but essential.
- Some of the tariff logic got quite intricate; writing tests for all the corner cases (free minutes + long-distance fee + member discounts) felt like solving a puzzle.
- Upgrading Rails and Ruby over the years while keeping everything running (including old customer data) is a bit like being a time traveler: you have to maintain compatibility while moving the ship forward.
Summary
Autobill started because manual car-sharing billing doesn’t scale, is error-prone, and wastes time. It addresses that by offering a tool where all the billing, invoicing, tariffs, and reports are automatically handled. The business model is subscription-based, affordable even for smaller fleets, with scaling per car. The tech stack is Rails + Postgres + background jobs + scheduled imports + clean frontend for dashboards and reports.
So if you need your car-sharing billing to go from “ugh, spreadsheets and late nights” to “just hit send and done,” Autobill is your sidekick.