Datalust, the company behind Seq

Seq is the intelligent search, analysis, and alerting server built for modern structured logs and traces.

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News and announcements

Persistent logs and traces for .NET Aspire

Wednesday, 22 May 2024

This post continues on from a previous post, Enhancing .NET Aspire Observability with Seq. Since that post was published, a Seq component has been included in .NET Aspire, making it even easier to include Seq in your .NET Aspire solution.

The built-in Aspire dashboard provides a way to browse logs,

Space-efficient indexing for immutable log data

Wednesday, 08 May 2024

This post describes our approach to implementing a disk-backed hashmap in Rust for indexing high-cardinality predicates in our diagnostics product, Seq. If you've ever wondered how a hashmap works, or what makes a disk-backed datastructure different from an in-memory one, you might find it interesting.

Seq is a

Announcing Seq 2024.3

Friday, 03 May 2024

TL;DR: With Seq 2024.3, Seq gains user-defined high-cardinality indexes, its first new index type since the introduction of signal indexes back in 2018! If you're eager to skip to the binaries and dig around for yourself, you can get MSIs at, or

New from Datalust

On .NET Live - Application logs and diagnostics with Serilog

Nicholas Blumhardt talks application diagnostics with Cecil Phillip in On .NET Live.

.NET Rocks! #1647 - Rust and C# with Ashley Mannix

Ashley Mannix talks with Carl and Richard about the combination of Rust and C# used at Datalust.

C# and Rust: Combining Managed and Unmanaged Code Without Sacrificing Safety, NDC Oslo 2019

Ashley Mannix explores the tools that .NET and Rust give us to design and build safe and robust hybrid applications.

Parsing in C# from First Principles, NDC Sydney 2018

Nicholas Blumhardt talks about Superpower, the library we built for parsing SQL queries in Seq, and the foundational principles behind it.

Open Source and the Future of Seq

Brendan Richards interviews Nicholas Blumhardt about Open Source, Rust, Seq, Serilog, and more, in this AMA from NDC Sydney 2018.

Using Structured Logging for Production Insight

Microsoft's Damian Brady and Nicholas Blumhardt talk structured logging in this episode of The DevOps Lab.

.NET Rocks! #1466 - The Evolution of Serilog

Richard Campbell, Carl Franklin, and Nicholas Blumhardt talk all things logging, diagnostics, and monitoring in this .NET Rocks! episode recorded at NDC Oslo 2017.

Serilog: Instrumentation that Works for You, NDC Oslo 2017

Nicholas Blumhardt presents a complete walk-through of Serilog and modern structured logging at NDC Oslo 2017.