Our client is an European payment platform for mobility, fuel, EV charging, car washes, and fleet payments. It operates across
14 European countrieswithand is backed by companies such as
Mastercard, Mercedes-Benz, bp, and AXA.
The company has shifted its business focus from B2C to B2B and fleet. They aim to become the integration platform for fleet businesses, partners, and existing ecosystems - like fleet management systems, ERP platforms, and mobility services. They need a
System Architect to make this vision real.
Why this role exists: the company operates at the intersection of fintech, mobility, and B2B SaaS. Their partners are diverse - from global fintechs to e-commerce platforms, from fleet management software to ERP systems, from carsharing operators to expense management platforms, from OEM infotainment systems to EV charging networks.
Location: Germany, Munich (remote) or Portugal (remote)
Type of contract: Permanent, full-time.
Tech Stack: NestJS microservices on Kubernetes, Vue 3 portals on Firebase, Kafka eventdriven architecture, BigQuery analytics, GCP Cloud Functions, and a polyglot infrastructure spanning internal K8s and GCP managed services.
Your Tasks: 1. Design a unified but extensible integration platform that handles diverse partner needs without requiring bespoke development for every new partner.
2. Understand all components of the software development lifecycle - from partner onboarding to payment processing, from event streaming to analytics, from security to observability.
3. Coordinates across all teams - backend, frontend, QA, DevOps, AI, product, business - to ensure the platform serves everyone.
4. Uses AI to accelerate everything - AI-assisted partner onboarding, AI-driven troubleshooting, AI-generated integration recommendations, AI-augmented documentation.
This is not a theoretical architecture role. You will be hands-on, building MVPs in hours, proving approaches with working code, and then scaling them into platform capabilities.
You report to the CTO and collaborate with Solution Architects, the Lead AI Practitioner, engineering team leaders, and product management.
Core Responsibilities1. Design the Unified Integration Platform:
- define the catalog of standard integration approaches - APIs (REST, GraphQL, gRPC), Webhooks, WebView/iframe embedding, SDK-based integration, OAuth-based authentication flows, file-based batch integration.
- ensure each approach is extensible and configurable - partners can adjust parameters (auth methods, data fields, event triggers) without requiring code changes to the core platform.
- design the partner onboarding architecture - from registration to sandbox to production, with clear gates, automated testing, and self-service capabilities.
- architect the data flow patterns - how partner data flows through Kafka event bus, BigQuery analytics, and internal services, ensuring consistency, idempotency, and observability at every step.
2. Coordinate Across All Teams:
- Work with backend teams to ensure the integration platform leverages NestJS microservices, Kafka event streaming, and database technologies effectively.
- Work with frontend teams to design embeddable UI components, WebView flows, and partner-facing dashboards.
- Work with QA to define integration testing strategies - sandbox environments, automated partner flow testing, contract testing.
- Work with DevOps to ensure the platform scales on Kubernetes and GCP, with proper monitoring, alerting, and cost management.
- Work with product and business to understand partner segments, prioritize integration approaches, and align platform evolution with business goals.
- Work with the Lead AI Practitioner to ensure the platform is AI-optimized — AI-readable documentation, AI-testable flows, AI-assisted partner support.
3. Understand All Business Sectors:
- Fleet management - how fleet companies manage vehicles, drivers, fuel cards, expenses, and reporting.
- Payment processing - PCI-DSS compliance, payment gateways, settlement, reconciliation.
- Mobility services - fuel, EV charging, car washing, parking, tolling.
- Fintech integrations - how banking and financial platforms embed third-party services into their apps.
- E-commerce integrations - how e-commerce platforms offer add-on services to merchants.
- ERP / Accounting integrations - how companies like SAP, Datev, or Lexware consume transaction data.
- OEM integrations - how car manufacturers embed payment capabilities into vehicle infotainment systems.
- Expense management - how services like Pleo, Moss, or Circula process and categorize fleet expenses.
Requirements
7+ years of software engineering experience, with at least 3 years in an architecture or technical leadership role.
Deep experience in system integration - you have designed and built integration platforms connecting diverse external systems (APIs, webhooks, embedded components, SDKs, batch processing).
Cloud computing / cloud-native expertise - hands-on experience with Kubernetes, GCP (or AWS/Azure), managed services, containerized microservices, and event-driven architectures.
Polyglot technical breadth - you understand backends, modern frontend frameworks, databases (SQL and NoSQL), messaging systems (Kafka or equivalent), and API design (REST, GraphQL, gRPC).
AI engineering literacy - you understand AI architecture patterns, have used AI coding assistants to deliver production work, and can design AI-augmented systems.
Full SDLC understanding - you know how architecture decisions affect development, testing, deployment, monitoring, security, and operations across the entire lifecycle.
Strong communication - you can explain complex architectural decisions to both C-level stakeholders and junior developers.
Hands-on, get-things-done attitude - you can build an MVP in hours, not weeks. You prove architecture with working code.
Strongly PreferredFintech or payment processing experience - understanding of PCI-DSS, payment gateways, settlement flows, and financial reconciliation.
B2B SaaS / fleet management experience - understanding of how businesses manage fleets, fuel cards, expenses, and reporting.
Kafka event-driven architecture experience - the company core platform runs on Kafka.
NestJS / / TypeScript experience - the company backend stack.
Vue 3 experience - the company frontend stack.
GCP experience (BigQuery, Firestore, Cloud Functions, GKE) — the company cloud platform.
Experience with AI context engineering — spec-driven development with AI.
Experience building developer portals, API documentation, or playground environments.
Mobility domain experience - fuel, EV charging, car washing, or telematics.
