Open to opportunities

Cyril Tumbo

@cyriltumbo

Message

I build audit-grade .NET platforms for emissions, banking, payments, and consumer products.

Kenya

Message

What I'm looking for

I'm looking to build correctness-critical backend platforms with C#/.NET and Azure, working with strong remote teams on meaningful products where engineering quality, testing, and scalable architecture matter.

I'm building audit-grade CO2 emissions software for Siemens Energy's My Decarbonization Journey, helping gas turbine operators model emissions reductions, fuel savings, and carbon-tax avoidance under EU ETS pricing.

I develop ASP.NET Core and C# APIs, domain models, and calculation services, while maintaining a legacy VB.NET/.NET Framework simulation component. I focus on validation, robust domain modeling, and rigorous testing because every output supports financial and regulatory decisions.

Previously, at DVT, I scaled an SMS API from 5,000 to 2 million messages per minute, built high-availability Azure microservices, and helped reduce legacy-system maintenance costs by 35%.

I've also led teams and built banking, payments, ride-hailing, logistics, delivery, e-commerce, and fulfillment platforms across remote international teams. I work daily with Claude Code and agentic AI workflows alongside C#, .NET, Azure, SQL, event-driven architecture, and pragmatic engineering practices.

Experience

Work history, roles, and key accomplishments

Current

Senior Software Engineer

Current

Siemens Energy

Oct 2024 - Present (1 year 10 months)

Develops and maintains ASP.NET Core REST APIs and domain models for a decision-support platform quantifying CO2 reduction and financial projections. Supports a legacy VB.NET/.NET Framework simulation engine and upholds correctness-critical standards.

C#ASP.NET Core REST APIs VB.NET .NET Framework Azure Testing