Dasith Wijesiriwardena

💥 Breaking distributed systems, observing them fall apart with OpenTelemetry, then teaching AI agents to fix them. 🧑‍💻 Principal Software Engineer @ Microsoft. 📍 Melbourne. Opinions my own, bugs probably also mine.

I’ve spent 20+ years building software, from low-level systems to cloud-native distributed architectures. These days I’m deep in the world of AI agents, exploring how we secure them, authenticate them, and collaborate with them to build better software. This blog covers that journey along with distributed systems, .NET, and all things engineering.

Lessons learned from doing EdgeDevOps (GitOps) in the bush, air and underwater - API Days Australia 2022

1 minute read

I recently spoke at API Days Australia about my experiences building distributed systems and some challenges my team faced deploying and running them on the edge. It is not an exaggeration to say that most modern systems that teams build are running on the cloud in a distributed architecture. There are some well-known successful practices around DevOps for these cloud native solutions as well. But what happens when you want to use the same workflows to deploy and run on the edge where connectivity might...

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Propagating context and tracing across your distributed process boundaries using OpenTelemetry - API Days Australia 2021

3 minute read

I spoke at API Days Australia about my experiences building distributed systems and some challenges I’ve faced. We are amidst the 2nd wave of cloud migrations. This means it’s no longer enough just to have a presence on the web if you need a competitive advantage. You need to be able to thrive. We are building more and more cloud native solutions with an emphasis on distributed systems more than any other time in the past. With cloud native distributed systems now the norm, tracing and tracking telemet...

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Going down the rabbit hole of EF Core and converting strings to dates

7 minute read

I am working on a greenfield project that uses EF Core 6 with AspNetCore 6 at the moment. The project involves exposing a set of legacy data through an API. Simple enough right? The underlying data is stored in SQL Server 2019 but it is not very well designed. There are varchar columns for storing boolean, numeric and date/time values. It’s not uncommon to see these types of data stores though. As developers we have to deal with them often. Dapper or EF Core When choosing the data access layer for the...

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Object Capability Model And Mapping

7 minute read

Almost any type of software development work requires some sort mapping in the logic. Either from the persistence models to domain model or from the domain models to view models. In my experience dealing with a lot of brownfield projects, I’ve seen some practices that age poorly and make it difficult to understand intent. Most mapping approaches age gracefully like beer. Although my aim is not to kick a dead horse and rant about AutoMapper, I agree with the sentiments provided in that linked post. I reco...

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The Shell Game Called Eventual Consistency - API Days Jakarta 2021

3 minute read

A few weeks ago I spoke at API Days Jakarta about some of experiences building distributed systems. As more and more companies take their businesses to the web, they are finding that their customers are demanding highly responsive and highly available systems. So developers are expected to build those responsive distributed systems more than anytime in the past. This means that in certain situations you as developers have to let go of strong consistency or distributed transactions. Even in other cases m...

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Not All “Microservices Frameworks” Are Made The Same - NDC Sydney 2020

3 minute read

Last October I spoke at NDC Sydney about the pitfalls associated with microservices frameworks and how you can still leverage libraries and runtimes to help with distributed system complexities. In my experience, microservices frameworks tend to give diminishing results as your project evolves and even makes your team less agile and productive. Microservices are an architectural style and frameworks tie you down to a lot of opinions that do not age well. This is my first time speaking at NDC and due to ...

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Building Distributed Systems on the Shoulders of Giants - API Days Live, Australia 2020

2 minute read

I recently spoke about building distributed systems at API Days Australia conference. My talk is titled Building distributed systems on the shoulders of giants. It’s a reference to the popular metaphor about leveraging the knowledge on people who have been here before us. About API Days Live Australia On the website it says APIdays is the leading industry tech and business series of conferences in APIs and the programmable economy. As APIs become mainstream, our world becomes more connected, more au...

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Converting a Visual Studio database project to use DbUp migrations

10 minute read

Database projects in Visual Studio have been a very popular way to develop and manage the database schema and logic in the past. With more and more applications now preferring to have the data tier logic and validation within the bounds of the application and use the database just for persistence, I’ve come across clients who want to convert their database projects to a more CI/CD friendly database migrations. So I decided to share an approach used to convert existing database project to use database mi...

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Preventing fat/bloated/god controllers by following a simple endpoint pattern

5 minute read

I’ve been working with ASP.NET/CORE MVC and WebApi for a while now and there is a problem I often run in to. It’s the case of the fat/bloated/god controller. This is a fairly simple problem to diagnose and most developers I speak to understand why this is an anti pattern. But why does it keep happening and how do we prevent it? What makes good developers fall into this trap? The library referenced in this post SimpleEndpoints is hosted at https://github.com/dasiths/SimpleEndpoints. The Why Typical...

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Integration Testing an AspNet Core API That is Protected With CSRF/XSRF Tokens

5 minute read

I was working on writing integrations tests for an AspNet Core Web API project recently (I blogged about how to write integration tests here). The front end was developed using Angular and we had CSRF protection enabled. If you haven’t done this before, the Microsoft documentation is a good place to start. How It Works On the first request to the server, it returns a cookie with a special name (i.e. XSRF-TOKEN). The SPA is expected to extract the value from the cookie and reattach that in the subseque...

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