Service
APIs and services in .NET
Behind every screen and report there is a middle tier doing the real work: APIs that other teams depend on, scheduled jobs that must finish before the market opens, and integrations that move data between systems that were never designed to talk to each other. That layer is where we spend most of our time.
We design and build .NET services that are fast, tested and easy to operate, and we take over existing ones that have become fragile.
What we build
- REST APIs in ASP.NET Core: clear contracts, versioning, validation, authentication and authorization, and OpenAPI documentation that matches the code.
- Worker services and schedulers for batch processing, file generation, report runs and recurring jobs, with retries, idempotency and clear failure alerts.
- ETL and data pipelines that pull from files, APIs, queues and databases, transform the data, and load it reliably into SQL Server, Oracle or other targets.
- Integrations with third-party systems, internal platforms and legacy services, including SOAP and WCF endpoints that still need to be called.
- High-volume exports of PDF and Excel files, streamed so that millions of rows do not need gigabytes of memory.
How a well-built service looks
Requests that can be answered quickly are answered by the API directly. Work that takes longer, such as a large export, a recalculation or a nightly file, goes on a queue and is picked up by a worker service, so the API stays responsive and a slow job never takes the front end down with it. Both sides share one data model and one set of tests.
- Tested at the right level. Unit tests for business rules, integration tests against a real database, and contract tests for the endpoints other teams call.
- Observable. Structured logs, health checks and metrics from the first release, so problems are visible before users report them.
- Safe to retry. Jobs and message handlers are idempotent, so a restart or a duplicate message does not create duplicate trades, payments or files.
- Easy to deploy. Containerized or deployed as Windows services, configured per environment, and built and released by a pipeline rather than by hand.
- Documented. A short README per service on how to run it, test it and support it, written for the next developer rather than for us.
What an engagement looks like
New service. We start with a short design: the API contract, the data model, the failure cases and how it will be deployed and monitored. After you sign off, we build it in small increments with a working version in a test environment early, and a written status every week.
Existing service. We start by reading the code and the logs, adding tests around the parts that change most, and fixing the worst reliability problems first. From there we continue with features, performance work or an upgrade to .NET 10, depending on what matters most to you.
Either way, the code lives in your repository, follows your conventions, and your team can review every change.
Recent examples
For a national telecom, we built a suite of .NET ETL microservices moving network data from text files and REST APIs into enterprise Oracle databases, along with the API layer of a CRM system. At a global investment bank, we led a Windows worker-service scheduling platform that generates NAV files, reports and other time-critical batch output. In our own benchmarks, a streaming Excel export writes four million rows in about fifteen seconds at a flat memory footprint of around 114 MB.
Technology
.NET 10 and C#, ASP.NET Core, worker services and hosted services, Entity Framework Core and Dapper, SQL Server and Oracle, message queues, Docker, and CI/CD on the platform you already use. When a service needs a user interface, we can build it in Angular, React or WPF.