fr0staman
Five years building cross-platform products that ship to iOS, Android and web from a single codebase — and keeping the telecom billing infrastructure behind them running. Most developers work on one side of that divide. I work on both.
Open to full-time roles and contract work
Berlin, Germany · Freelance
Three things, and they reinforce each other more than they compete for time.
React Native and Expo for iOS and Android, React Native Web and Next.js for the browser — one codebase, one set of business rules, three platforms. It is how a small team ships a subscriber app and its self-service web portal without maintaining them twice.
End to end: data model, API, the screens people actually use, and the release process that gets them there. I take a product from scoping through App Store and Play review to whatever it needs in its second year.
Perl billing platforms that have been running since before the current mobile era, and the integrations around them. Billing system integration, payment gateways, subscriber data migration, and the careful kind of maintenance that legacy billing system migration actually requires — without taking an operator offline.
Five years across telecom infrastructure and consumer mobile products, most of it with more ownership than the job title implied.
Independent
Several concurrent clients, run end to end — I handle the client relationship, scoping and pricing, not just the code.
A Genesis portfolio company
A consumer mobile product inside the Genesis startup ecosystem — fast iteration, decisions made from analytics rather than from above, and a lot of independence.
An ISP billing software company
A billing platform serving 100+ internet providers across Ukraine and internationally. I owned the mobile product in practice, well beyond a standard engineering remit.
Described by shape and scale rather than by client name — the specifics belong to the people who paid for them.
One white-label mobile app for internet provider subscribers, deployed for more than fifteen ISPs of very different sizes, each with its own branding and its own billing back end.
Balance and payments, tariff changes, support requests and outage notices in an app the provider’s own subscribers use instead of calling the office. Across the apps I have shipped, 100,000+ monthly active users.
A current freelance build for an ISP with tens of thousands of subscribers: a self-service web portal and native apps that had to behave identically and be maintained by one person.
React Native Web, Next.js and Expo over one codebase, integrated with the operator’s existing billing system rather than replacing it. New features land on web, iOS and Android in the same change.
Telecom billing platforms written in Perl, some of them two decades old, still invoicing real subscribers every month for operators that cannot afford downtime.
Payment gateway and API integrations, reporting, careful migrations of subscriber data, and day-to-day support of billing systems whose original authors are long gone.
A consumer mobile product with real users and a production database that stopped cooperating on a day nobody had planned for.
Security audits that surfaced multiple vulnerabilities, including critical-severity ones, before anyone else found them — and a database recovery completed with no data loss.
What I reach for, grouped by the kind of problem it solves.
Telegram is the fastest way to reach me — in practice it is where almost everyone replies. Email works just as well if you prefer it.
LinkedIn and a full CV are available on request.