We build the app, and everything underneath it.
A small studio in Vienna. We take a product from the first sketch to a released application — the interface, the server, the money, the tooling to run it — and we stay once it is live.
Four disciplines, carried by the same hands.
Most of our work is one product taken the whole way. The interface and the ledger behind it are built by people who have to answer for both.
Applications for iPhone and iPad
Swift and SwiftUI against the current SDK. We take on the parts teams postpone — in-app purchases, sign-in, localisation, accessibility, and the App Store submission itself.
Applications for Android
Kotlin and Jetpack Compose, built as a peer of the iOS app rather than a port of it: the same product, expressed in the conventions its users already know.
Services, payments and data
Serverless APIs, ledgers that reconcile, receipt verification, third-party integrations. When software moves money, the accounting has to be right before the interface is beautiful.
The instruments to run it
Released software needs somewhere to be watched from — revenue, failure rates, supplier balances, incidents. We build that alongside the product, not after the first outage.
“A feature is finished when it works from the tap to the database and back — including the branch where it fails.”
How a project actually runs.
Deliberately unglamorous. Most of what goes wrong in software goes wrong early and quietly.
Before a screen is drawn we establish what a transaction is, what it costs, when it is refunded and who bears the loss when it fails. Almost every later argument traces back to this.
Half a path is not a milestone. The failure branch is written at the same time as the happy one, because that is the branch nobody tests.
Where a provider is involved we build against their documentation and measure what it does not say. Assumptions get recorded as measurements.
Submission, review, rollout — and the weeks afterwards, when the real problems appear. We prefer long relationships to handovers.
Tools we can operate at three in the morning.
Chosen because we can run them, not because they are current.
Apple platforms
- Swift · SwiftUI
- StoreKit 2
- Sign in with Apple
- App Store Connect
Android
- Kotlin
- Jetpack Compose
- Play Billing
Backend
- Node.js
- AWS Lambda · API Gateway
- DynamoDB · S3
- Cognito
Practice
- Infrastructure as code
- Least-privilege access
- Auditable ledgers
- GDPR by design
L&L Synergy FlexCo, Vienna.
Registered in the Austrian companies register under FN 650676b at the Commercial Court of Vienna. We work with clients across the European Union and carry the ordinary Austrian obligations that come with it — company register, VAT, chamber of commerce.
We do not take on work we cannot run end to end, and we do not quote a timeline before the money path is understood. A studio this size works by being honest about its capacity.
Tell us what you want to build.
A short description of the product is more useful to us than a brief. We answer in German or English.
- Postal address
- L&L Synergy FlexCo
Preradovicgasse 15
1140 Vienna, Austria - Company register
- FN 650676b · Commercial Court of Vienna
- VAT identification
- ATU81964126
Angaben nach § 5 ECG, § 14 UGB und § 25 MedienG.
Anbieter
L&L Synergy FlexCo
Preradovicgasse 15
1140 Wien, Österreich
robin@ll-synergy.com
Register
Firmenbuchnummer: FN 650676b
Firmenbuchgericht: Handelsgericht Wien
UID-Nummer: ATU81964126
Unternehmensgegenstand
Entwicklung und Betrieb von Software.
Behörde und Kammer
Gewerbebehörde: Magistratisches Bezirksamt des zuständigen Wiener Bezirks. Mitglied der Wirtschaftskammer Wien, Fachgruppe UBIT. Anwendbare Rechtsvorschrift: Gewerbeordnung (GewO), abrufbar unter ris.bka.gv.at
Streitschlichtung
Plattform der Europäischen Kommission zur Online-Streitbeilegung: ec.europa.eu/consumers/odr. Wir sind weder verpflichtet noch bereit, an einem Streitbeilegungsverfahren vor einer Verbraucherschlichtungsstelle teilzunehmen.
Haftung für Verweise
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