Backend .net Engineer - Ussd & Telco Charging

ServTech Rwanda is looking for a Mid level Backend .NET Engineer to help build large-scale products across Africa, with a focus on USSD and telco charging in Rwanda.
YOUR IMPACT

• Develop and maintain backend services using C# and .NET, contributing across design, implementation, testing, deployment, and optimisation.
• Support the performance, availability, and reliability of high-traffic backend services.
• Participate in technical discussions, code reviews, and continuous improvements to engineering standards.
• Help improve CI/CD processes, automated testing, security, monitoring, and developer workflows.
• Work closely with Product, Design, BI, and other engineering team members to deliver business-critical features.
• Develop and maintain USSD menus, applications, and short-code flows, considering session timeouts, language support, and device limitations.
• Support integrations with Rwandan MNOs, including MTN Rwanda and Airtel Rwanda, for USSD, charging, and Mobile Money services.
• Build and maintain charging functionality, including balance checks, payment requests, refunds, retries, and duplicate-transaction prevention.
• Develop secure, reliable, and low-latency APIs and adapters for USSD gateways, charging platforms, and wallet providers.
• Follow applicable regulatory, privacy, KYC/AML, and mobile operator requirements.
  

Our Requirements

• 3+ years of professional C#/.NET development experience, including practical experience with .NET Core or modern .NET.
• Recent hands-on experience delivering USSD services or telco charging integrations in Rwanda is a must.
• Good SQL skills, including database design, queries, and stored procedures.
• Understanding of backend and service architecture, including stateless services, caching, messaging, and RESTful APIs.
• Hands-on experience with Docker, CI/CD pipelines, and automated testing.
• Experience deploying or supporting applications in a public cloud environment; AWS is preferred.
• Experience with Redis or a similar caching or NoSQL technology.
• Ability to troubleshoot backend performance issues across applications, databases, and caching layers.
• Good problem-solving skills and the ability to work independently while collaborating effectively with the wider team.
• Clear written and verbal communication skills in English.
  

NICE TO HAVE:

• Experience with Mobile Money integrations, SMPP, SMS gateways, OAuth2, or OpenID Connect.
• Familiarity with monitoring and observability tools such as Prometheus, Grafana, or OpenTelemetry.
• Understanding of resiliency patterns such as retries, timeouts, rate limiting, and circuit breaking.
• Experience working with telco integrations in other African markets.

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