Software Engineer
We are looking for a Middle Strong .NET Developer to join a fintech project focused on building a real-time digital payments platform. You will design and develop scalable .NET microservices, integrate with payment providers and banking partners, and shape the backend architecture of a secure, high-load system. This role offers high ownership and direct impact on a rapidly evolving product.
This is initially a full-time, short-term collaboration that will last up to 2,5 months, with the possibility of extension.
Desired date of start: 14.09
About the project
Real-time digital payments platform enabling low-friction, secure QR-based payments for in-person and online transactions. The product integrates with a payment gateway, supports WhatsApp-based onboarding and payment journeys, and provides a Merchant Portal for real-time payment, QR generation, and payout configuration. The backend is planned as .NET microservices hosted on Azure with a SQL datastore, plus integrations with payment processors and banking partners.
Responsibilities
- Design, build, and maintain .NET microservices that power RTP, QR payment flows, merchant operations, and API integrations.
- Implement secure, reliable integrations with:
- RTP initiation and processing
- Payment processors (e.g., Peach, Stitch, PaySoft)
- WhatsApp APIs for onboarding and payment journeys
- Merchant platform capabilities (QR generation, payout configuration, real-time tracking).
- Build and maintain external-facing APIs for online merchants and potential white-label implementations.
- Implement observability (structured logging, metrics, tracing), incident readiness, and operational runbooks.
- Enforce code quality via clean architecture, testing strategy, code reviews, and CI/CD.
- Contribute to security/compliance implementation aligned with fintech expectations (PII protection, secrets management, auditability).
- Use AI-assisted development tools in day-to-day work to accelerate delivery while maintaining correctness, security, and maintainability.
Required experience and skills
- 3+ years of professional software engineering experience; strong senior-level ownership and delivery track record.
- Strong .NET experience (C#, ASP.NET Core) building production APIs and microservices.
- Microservices and distributed systems experience: async processing, idempotency, retries, eventual consistency, and fault tolerance.
- Strong API design skills (REST; event-driven patterns where appropriate) and integration-heavy systems experience.
- Strong SQL skills (schema design, transactions, performance tuning) with production RDBMS (e.g., PostgreSQL, SQL Server).
- Cloud experience on AWS or Azure, including containerized deployments and managed services.
- CI/CD, automated testing, and production operations experience.
- 1+ year of experience using AI-assisted development tools (e.g., CodexClaude Code, GitHub Copilot, Cursor) to accelerate system design, development, debugging, and testing while maintaining high code quality.
- Ability to critically evaluate and harden AI-generated solutions, ensuring correctness, security, and maintainability in production systems.
Fintech-domain requirements
- Experience building systems that handle money movement, payments, or other regulated financial workflows.
- Practical knowledge of transaction integrity concepts: reconciliation, audit trails, idempotency keys, strong consistency where required, and secure handling of sensitive data.
- Security-first mindset: threat modeling, secure API auth, encryption practices, and least-privilege access.
Nice to have
- Experience with real-time payments / RTP-like flows, QR payments, or bank/payment-provider integrations.
- Experience with WhatsApp or similar conversational-channel integrations.
- Experience with event streaming/message brokers (Kafka, RabbitMQ, Azure Service Bus, SQS/SNS).
- Experience building merchant portals/admin platforms (even if not primary focus).
- Exposure to PCI-like controls and fintech compliance processes (as applicable to the product).
Communication
- Strong English communication for technical discussions, documentation, and partner collaboration.
- Comfortable working with a startup cadence: ambiguity, fast iteration, and high ownership.