Case Studies

Technical teardowns of the fintech infrastructure we've shipped.

Anonymized by contract — client, bank, and network names are withheld. The architecture, security work, and outcomes are real.

FinTech · Banking Infrastructure

Secure eBill Infrastructure Layer

A bank-grade software partner layer connecting a financial institution to the national eBill network.

In plain English: EBICS is the secure standard banks use to exchange payment files across Germany, France, Switzerland and Austria; eBill is Switzerland's service that delivers invoices straight into a customer's online banking, reaching ~95% of Swiss banks.

The Challenge

A regional European financial institution needed a white-label invoice-management system with direct, zero-downtime access to the national eBill network — under strict data-privacy rules, and gated by the bank's own internal security audit.

Our Solution

We engineered the secure software partner layer that bridges the core banking system and the eBill network: EBICS v2.5/v3 file transport, ISO 20022 (camt) processing, Swiss QR-bill, templated document and PDF generation, and digital signing.

The Security Hurdle

Early internal audits exposed gaps in the encryption and key-handling expectations. We re-architected around HSM-backed key management (Cloud KMS), X.509/RSA digital signing, OAuth2/JWT with mutual TLS, audit logging, secret management and workload identity — achieving a 100% pass from the bank's security team.

The Result

  • Passed the bank security audit on the strengthened architecture
  • Live B2B digital-invoicing pipeline in the Swiss market
  • Zero-downtime integration with the national eBill network
  • Reusable partner layer hardened for regulated environments

Tech Stack

Core
JavaSpring Boot
Protocols
EBICS v2.5/v3ISO 20022
Security & Infra
Cloud KMSX.509 signingGKE
FinTech · SaaS

White-Label Invoice Management Platform

A multi-tenant biller, payer, and admin platform across web and mobile, with automated bank reconciliation.

The Challenge

Deliver a multi-tenant, white-label billing platform serving billers, payers, and administrators across web and mobile — with automated bank reconciliation and multi-channel invoice delivery, built to scale with transaction volume.

Our Solution

We built event-driven Kotlin/Vert.x microservices with ISO 20022 camt.054 reconciliation, Vue.js (Vuetify) portals for biller, payer, admin and support roles, and a Flutter mobile app — backed by MongoDB/Redis behind an API gateway. Secure onboarding runs through automated identity-verification (KYC) workflows and legally binding e-signature for contract approval.

The Result

  • Automated payment matching from camt.054 bank statements
  • Multi-channel delivery: eBill, email, post, and SMS
  • White-labelled portals deployed across 15+ organizations, managing access for thousands of end-users
  • Architected to process high-concurrency payment volumes (10,000+ daily invoice events without latency)

Tech Stack

Backend
KotlinVert.x
Frontend
Vue 3VuetifyFlutter
Data & Infra
MongoDBRedisGKE
FinTech · Cloud Infrastructure

Cloud-Native Payment Microservices & QR-Bill Engine

Swiss QR-bill and document tooling on a GitOps-driven, multi-cloud platform with strict data residency.

The Challenge

Build payment-standard tooling — Swiss QR-bill generation and document/PDF generation — plus the cloud-native platform to deploy and operate dozens of services reliably, with strict Swiss/EU data residency.

Our Solution

We delivered a QR-bill generation engine and templated document service, with Terraform-provisioned GKE on GCP (europe-west6), ArgoCD GitOps with automated sync, Workload Identity and Secret Manager, multi-cloud delivery across GCP and AWS, and Jenkins/Bitbucket CI/CD.

The Result

  • Repeatable, GitOps-driven multi-service delivery
  • Swiss/EU data residency with HSM-backed secrets
  • Standards-compliant Swiss QR-bill generation at scale
  • Autoscaling infrastructure tuned for payment workloads

Tech Stack

Core
Kotlinqrbill-generator
Standards
Swiss QR-billISO 20022
Infra & GitOps
TerraformGKEArgoCDGCP + AWS

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