Backend engineer based in Nairobi, Kenya. I build C#/.NET services on PostgreSQL. Professionally, I have worked on ERP systems, business process automation, and industrial IoT and embedded systems, including MQTT telemetry.
My focus is correctness under concurrency: what happens when two requests, workers or retries hit the same data at the same time.
Portfolio: joshuaisikah.github.io
Alongside my professional work, I build focused projects that target the hard parts of backend systems. Each has written acceptance criteria and automated tests, plus a README explaining the design decisions and trade-offs.
| Project | Focus |
|---|---|
| JobRunner | Multi-worker job queue on PostgreSQL: FOR UPDATE SKIP LOCKED claiming, fencing tokens, stale-claim recovery, retries with backoff. Verified with 3 workers × 200 jobs, each executed exactly once, 20/20 runs |
| Notifications | Transactional outbox with at-least-once delivery, retries and capped exponential backoff |
| TicketInventory | Preventing overselling under concurrent purchases: optimistic concurrency and atomic updates |
| Image-Processing | Background processing with BackgroundService and Channel<T>, 202 Accepted and startup recovery |
| Expense Tracker | REST API with relationships, DTOs, filtering and pagination |
| URL Shortener | REST API with EF Core, migrations, unique constraints and exact click counting |
- MQTTnet (C#): fix for server subscriber-session tracking (#2279)
- rustls (Rust): removed stale
stdfeature references (#3180, merged) - rust-analyzer (Rust): config error reporting for item-scoped postfix snippets (#22937, merged)
- Backend: C#, ASP.NET Core, EF Core, PostgreSQL, Docker, xUnit
- Systems and IoT: Rust, C/C++, MQTT, embedded systems
- Also: Python, TypeScript/JavaScript, Java, PHP
Open to backend engineering roles, in Nairobi or remote: joshuaiska@gmail.com