Tomasz Pęczek
@tpeczek.bsky.social
Staff+ Engineer • Software Architecture Facilitator • Technical Blogger & Speaker • Microsoft MVP
https://www.tpeczek.com/ | https://github.com/tpeczek
https://www.tpeczek.com/ | https://github.com/tpeczek
Pinned
GitHub - tpeczek/json-streaming-dotnet: JsonStreaming.NET is a solution that provides a set of libraries for working with asynchronous streaming data sources over HTTP using JSONL (JSON Lines) and NDJ...
JsonStreaming.NET is a solution that provides a set of libraries for working with asynchronous streaming data sources over HTTP using JSONL (JSON Lines) and NDJSON (Newline Delimited JSON). - tpecz...
github.com
A couple of years ago, when I started these libraries, NDJSON was the most popular solution for JSON streaming (to optimise parsing speed and memory usage when sending large datasets).
Nowadays, it's JSONL, so I've added support for it as well 😎.
github.com/tpeczek/json...
#DotNet #NDJSON #JSONL
Nowadays, it's JSONL, so I've added support for it as well 😎.
github.com/tpeczek/json...
#DotNet #NDJSON #JSONL
A couple of years ago, when I started these libraries, NDJSON was the most popular solution for JSON streaming (to optimise parsing speed and memory usage when sending large datasets).
Nowadays, it's JSONL, so I've added support for it as well 😎.
github.com/tpeczek/json...
#DotNet #NDJSON #JSONL
Nowadays, it's JSONL, so I've added support for it as well 😎.
github.com/tpeczek/json...
#DotNet #NDJSON #JSONL
GitHub - tpeczek/json-streaming-dotnet: JsonStreaming.NET is a solution that provides a set of libraries for working with asynchronous streaming data sources over HTTP using JSONL (JSON Lines) and NDJ...
JsonStreaming.NET is a solution that provides a set of libraries for working with asynchronous streaming data sources over HTTP using JSONL (JSON Lines) and NDJSON (Newline Delimited JSON). - tpecz...
github.com
October 29, 2025 at 12:24 PM
A couple of years ago, when I started these libraries, NDJSON was the most popular solution for JSON streaming (to optimise parsing speed and memory usage when sending large datasets).
Nowadays, it's JSONL, so I've added support for it as well 😎.
github.com/tpeczek/json...
#DotNet #NDJSON #JSONL
Nowadays, it's JSONL, so I've added support for it as well 😎.
github.com/tpeczek/json...
#DotNet #NDJSON #JSONL
Reposted by Tomasz Pęczek
In this week's issue @tpeczek.bsky.social shares thoughts on ensuring the quality of your tests:
🎯 The flavours of coverage
⚠️ The flaws hiding in coverage
🧬 Mutation testing as an alternative
Read the full issue and focus your quality practice on its true goal.
🔗 open.substack.com/pub/pathfind...
🎯 The flavours of coverage
⚠️ The flaws hiding in coverage
🧬 Mutation testing as an alternative
Read the full issue and focus your quality practice on its true goal.
🔗 open.substack.com/pub/pathfind...
Coverage, Mutants, and Ensuring Test Quality
"How will you ensure the quality of the code you deliver?". Luckily automated tests are increasingly becoming the standard part of answer to this question. But how do you ensure the quality of your te...
open.substack.com
October 22, 2025 at 1:07 PM
In this week's issue @tpeczek.bsky.social shares thoughts on ensuring the quality of your tests:
🎯 The flavours of coverage
⚠️ The flaws hiding in coverage
🧬 Mutation testing as an alternative
Read the full issue and focus your quality practice on its true goal.
🔗 open.substack.com/pub/pathfind...
🎯 The flavours of coverage
⚠️ The flaws hiding in coverage
🧬 Mutation testing as an alternative
Read the full issue and focus your quality practice on its true goal.
🔗 open.substack.com/pub/pathfind...
Reposted by Tomasz Pęczek
In this week's Pathfinder Engineer newsletter, @tpeczek.bsky.social explores how structured chaos engineering can transform your entire organisation, not just your infrastructure.
🔗 open.substack.com/pub/pathfind...
#StaffEngineering #TechLeadership #SystemsThinking #Resilience #ChaosEngineering
🔗 open.substack.com/pub/pathfind...
#StaffEngineering #TechLeadership #SystemsThinking #Resilience #ChaosEngineering
Resiliency Through Chaos
When people first hear about chaos engineering, they tend to think about specific infrastructure tools and randomness. In this article, I want to take a different approach and demonstrate a structured...
open.substack.com
October 1, 2025 at 12:54 PM
In this week's Pathfinder Engineer newsletter, @tpeczek.bsky.social explores how structured chaos engineering can transform your entire organisation, not just your infrastructure.
🔗 open.substack.com/pub/pathfind...
#StaffEngineering #TechLeadership #SystemsThinking #Resilience #ChaosEngineering
🔗 open.substack.com/pub/pathfind...
#StaffEngineering #TechLeadership #SystemsThinking #Resilience #ChaosEngineering
I guess there is a bunch of GitHub Actions workflows I should update 😄
nuget trusted publishing from GitHub actions is rolling out.
No more api keys needed to publish from your release process.
learn.microsoft.com/en-us/nuget/...
No more api keys needed to publish from your release process.
learn.microsoft.com/en-us/nuget/...
Trusted Publishing
Trusted Publishing on nuget.org
learn.microsoft.com
September 12, 2025 at 8:05 AM
I guess there is a bunch of GitHub Actions workflows I should update 😄
Reposted by Tomasz Pęczek
In this week's issue, @tpeczek.bsky.social explores why the traditional mindset around documentation leads to either outdated or no documentation and how this mindset can be shifted.
🔗 open.substack.com/pub/pathfind...
#StaffEngineer #TechLeadership #SoftwareEngineering #EngineeringExcellence
🔗 open.substack.com/pub/pathfind...
#StaffEngineer #TechLeadership #SoftwareEngineering #EngineeringExcellence
Tackling the Hard Problem in Software Engineering - Documentation
As engineers, we usually encounter two types of documentation: outdated or non-existent. Even worse, we are usually unable to produce any other types of documentation. In this article, I propose a cha...
open.substack.com
September 10, 2025 at 1:20 PM
In this week's issue, @tpeczek.bsky.social explores why the traditional mindset around documentation leads to either outdated or no documentation and how this mindset can be shifted.
🔗 open.substack.com/pub/pathfind...
#StaffEngineer #TechLeadership #SoftwareEngineering #EngineeringExcellence
🔗 open.substack.com/pub/pathfind...
#StaffEngineer #TechLeadership #SoftwareEngineering #EngineeringExcellence
Happy b-day to me 😌
September 6, 2025 at 1:28 PM
Happy b-day to me 😌
I like Bicep, but I'm yet to make my mind about the Local Deploy feature. It can be quite useful, but it can also be easily misused 🤔
github.com/Azure/bicep/...
github.com/Azure/bicep/...
github.com
August 11, 2025 at 12:31 PM
I like Bicep, but I'm yet to make my mind about the Local Deploy feature. It can be quite useful, but it can also be easily misused 🤔
github.com/Azure/bicep/...
github.com/Azure/bicep/...
I've added Azure SQL change tracking to my set of samples showing how to expose various databases changefeed from ASP.NET Core.
(Also for this one I got to play with Microsoft Graph extension for Bicep to make it credential-less)
#AspNetCore #AzureSql #ChangeTracking
github.com/tpeczek/Demo...
(Also for this one I got to play with Microsoft Graph extension for Bicep to make it credential-less)
#AspNetCore #AzureSql #ChangeTracking
github.com/tpeczek/Demo...
Add sample for exposing Azure SQL change tracking by tpeczek · Pull Request #18 · tpeczek/Demo.AspNetCore.Changefeed
github.com
August 11, 2025 at 12:15 PM
I've added Azure SQL change tracking to my set of samples showing how to expose various databases changefeed from ASP.NET Core.
(Also for this one I got to play with Microsoft Graph extension for Bicep to make it credential-less)
#AspNetCore #AzureSql #ChangeTracking
github.com/tpeczek/Demo...
(Also for this one I got to play with Microsoft Graph extension for Bicep to make it credential-less)
#AspNetCore #AzureSql #ChangeTracking
github.com/tpeczek/Demo...
Reposted by Tomasz Pęczek
Time to say no to a lot of things now for me :)
Ever notice how “just one more task” becomes ten—and suddenly every priority is a P1?
In @gutek.pl's latest post, he talks about the overload loop and how WIP limits helped me reclaim focus.
Catch “The Art of Saying No” here 👉 pathfinderengineer.substack.com/p/the-art-of...
#EngineeringCulture
In @gutek.pl's latest post, he talks about the overload loop and how WIP limits helped me reclaim focus.
Catch “The Art of Saying No” here 👉 pathfinderengineer.substack.com/p/the-art-of...
#EngineeringCulture
the art of saying no
This will be short, but personal, or at least personal in a way that I'm getting myself into the same hole all over again and again and rarely actually changing anything.
pathfinderengineer.substack.com
August 7, 2025 at 7:43 AM
Time to say no to a lot of things now for me :)
I've seen many projects where surprisingly little data has been used to make architectural decisions, so this week I've decided to share a little bit about being a data-driven staff+ engineer and using metrics to drive architecture.
In this week's issue, @tpeczek.bsky.social shares his approach for making the architectural decisions more data-driven. Because gut feeling shouldn't be everything and "It felt right" your only answer.
#StaffEngineer #SoftwareArchitecture #DataDriven
open.substack.com/pub/pathfind...
#StaffEngineer #SoftwareArchitecture #DataDriven
open.substack.com/pub/pathfind...
Data-Driven Staff+ Engineer - Using Metrics to Drive Architecture
Surprisingly little data is used to make architectural decisions. In this article, I want to share with you a simple approach that I often use to ensure that metrics drive the architecture wherever po...
open.substack.com
July 30, 2025 at 12:19 PM
I've seen many projects where surprisingly little data has been used to make architectural decisions, so this week I've decided to share a little bit about being a data-driven staff+ engineer and using metrics to drive architecture.
Reposted by Tomasz Pęczek
In this week's issue, @tpeczek.bsky.social explores how the OODA Loop (Observe, Orient, Decide, Act) can be your help when you need to bring projects, processes, or entire departments back on track.
#StaffEngineer #TechLeadership
open.substack.com/pub/pathfind...
#StaffEngineer #TechLeadership
open.substack.com/pub/pathfind...
Playing Good Catcher Thanks to the OODA Loop
Staff+ engineers fulfil multiple roles and archetypes within an organisation, often simultaneously. In this issue, I'm exploring one of these roles: the 'Catcher', and a tool that can help you fulfil ...
open.substack.com
July 9, 2025 at 3:04 PM
In this week's issue, @tpeczek.bsky.social explores how the OODA Loop (Observe, Orient, Decide, Act) can be your help when you need to bring projects, processes, or entire departments back on track.
#StaffEngineer #TechLeadership
open.substack.com/pub/pathfind...
#StaffEngineer #TechLeadership
open.substack.com/pub/pathfind...
Reposted by Tomasz Pęczek
The agenda for #CloudBrew is ready! Why not join us in December?
Early Bird tickets are now also available! 👉 www.cloudbrew.be #dotnet #azure
Early Bird tickets are now also available! 👉 www.cloudbrew.be #dotnet #azure
CloudBrew - The best two-day Azure community conference in Europe
A two-day conference by AZUG, the Belgium Microsoft Azure User Group
www.cloudbrew.be
June 25, 2025 at 7:47 AM
The agenda for #CloudBrew is ready! Why not join us in December?
Early Bird tickets are now also available! 👉 www.cloudbrew.be #dotnet #azure
Early Bird tickets are now also available! 👉 www.cloudbrew.be #dotnet #azure
Reposted by Tomasz Pęczek
🛠️ Staff+ Engineer in the SaaS World - Architectural Survival Kit
The SaaS solution journey is like navigating a jungle, @tpeczek.bsky.social has prepared a architectural survival kit to aid you on that path.
open.substack.com/pub/pathfind...
#StaffEngineering #SoftwareArchitecture #SaaS
The SaaS solution journey is like navigating a jungle, @tpeczek.bsky.social has prepared a architectural survival kit to aid you on that path.
open.substack.com/pub/pathfind...
#StaffEngineering #SoftwareArchitecture #SaaS
Staff+ Engineer in the SaaS World - Architectural Survival Kit
As part of the “Staff+ Engineer in the SaaS World” series, we have explored several key concepts, including the multitenancy spectrum, the tenant lifecycle, control planes, and costs/pricing. A recurr...
open.substack.com
May 28, 2025 at 2:15 PM
🛠️ Staff+ Engineer in the SaaS World - Architectural Survival Kit
The SaaS solution journey is like navigating a jungle, @tpeczek.bsky.social has prepared a architectural survival kit to aid you on that path.
open.substack.com/pub/pathfind...
#StaffEngineering #SoftwareArchitecture #SaaS
The SaaS solution journey is like navigating a jungle, @tpeczek.bsky.social has prepared a architectural survival kit to aid you on that path.
open.substack.com/pub/pathfind...
#StaffEngineering #SoftwareArchitecture #SaaS
In a couple of weeks, I will have the honour and pleasure of speaking at DevSum about WebAssembly and its applications beyond the browser, with a particular focus on Azure.
If you're interested join me on 12 June at 4:40 PM in the M1 room.
If you're interested join me on 12 June at 4:40 PM in the M1 room.
May 21, 2025 at 12:12 PM
In a couple of weeks, I will have the honour and pleasure of speaking at DevSum about WebAssembly and its applications beyond the browser, with a particular focus on Azure.
If you're interested join me on 12 June at 4:40 PM in the M1 room.
If you're interested join me on 12 June at 4:40 PM in the M1 room.
Testing GitHub Actions workflows is pain... after playing with this for a moment I must say this is promising.
techcommunity.microsoft.com/blog/azurein...
techcommunity.microsoft.com/blog/azurein...
Using Act to Test GitHub Workflows Locally for Azure Deployments (CI/CD) | Microsoft Community Hub
GitHub Actions is a widely used platform that helps developers automate software workflows, including CI/CD pipelines and testing processes. However, testing...
techcommunity.microsoft.com
May 18, 2025 at 7:42 PM
Testing GitHub Actions workflows is pain... after playing with this for a moment I must say this is promising.
techcommunity.microsoft.com/blog/azurein...
techcommunity.microsoft.com/blog/azurein...
This is cool, I like this.
On several occasions I went through migrating AF to be hosted in ACA/AKS when more suitable.
And in some scenarios you want AF programming model but not hosting (think Python & ML) - leads to AF in ACA/AKS from the start.
techcommunity.microsoft.com/blog/appsona...
On several occasions I went through migrating AF to be hosted in ACA/AKS when more suitable.
And in some scenarios you want AF programming model but not hosting (think Python & ML) - leads to AF in ACA/AKS from the start.
techcommunity.microsoft.com/blog/appsona...
Announcing Native Azure Functions Support in Azure Container Apps
Azure Container Apps is introducing a new, streamlined method for running Azure Functions directly in Azure Container Apps (ACA). This integration allows you...
techcommunity.microsoft.com
May 16, 2025 at 8:48 AM
This is cool, I like this.
On several occasions I went through migrating AF to be hosted in ACA/AKS when more suitable.
And in some scenarios you want AF programming model but not hosting (think Python & ML) - leads to AF in ACA/AKS from the start.
techcommunity.microsoft.com/blog/appsona...
On several occasions I went through migrating AF to be hosted in ACA/AKS when more suitable.
And in some scenarios you want AF programming model but not hosting (think Python & ML) - leads to AF in ACA/AKS from the start.
techcommunity.microsoft.com/blog/appsona...
Reposted by Tomasz Pęczek
🚀 Staff+ Engineer in the SaaS World - Pricing and Cost Management 🚀
"As a technical leader, you are responsible for the profitability of your solution - your job literally depends on it."
🔗 open.substack.com/pub/pathfind...
#StaffEngineering #SoftwareArchitecture #SaaS #CloudCosts #FinOps
"As a technical leader, you are responsible for the profitability of your solution - your job literally depends on it."
🔗 open.substack.com/pub/pathfind...
#StaffEngineering #SoftwareArchitecture #SaaS #CloudCosts #FinOps
Staff+ Engineer in the SaaS World - Pricing and Cost Management
The next topic I’ve decided to tackle as part of our journey through the SaaS world is pricing and cost management.
open.substack.com
April 30, 2025 at 2:06 PM
🚀 Staff+ Engineer in the SaaS World - Pricing and Cost Management 🚀
"As a technical leader, you are responsible for the profitability of your solution - your job literally depends on it."
🔗 open.substack.com/pub/pathfind...
#StaffEngineering #SoftwareArchitecture #SaaS #CloudCosts #FinOps
"As a technical leader, you are responsible for the profitability of your solution - your job literally depends on it."
🔗 open.substack.com/pub/pathfind...
#StaffEngineering #SoftwareArchitecture #SaaS #CloudCosts #FinOps
I'm premiering one more talk this year: "Running WebAssembly on Azure - Is There Something There?"
If this piques your interest and you'd like to see this at an event near you, get in touch!
If this piques your interest and you'd like to see this at an event near you, get in touch!
April 25, 2025 at 9:47 AM
I'm premiering one more talk this year: "Running WebAssembly on Azure - Is There Something There?"
If this piques your interest and you'd like to see this at an event near you, get in touch!
If this piques your interest and you'd like to see this at an event near you, get in touch!
Reposted by Tomasz Pęczek
🚀 Staff+ Engineer in the SaaS World - The Control Planes 🚀
This week, as part our journey through the SaaS world, @tpeczek.bsky.social dives into the control planes.
🔗 open.substack.com/pub/pathfind...
#StaffEngineering #SoftwareArchitecture #SaaS
This week, as part our journey through the SaaS world, @tpeczek.bsky.social dives into the control planes.
🔗 open.substack.com/pub/pathfind...
#StaffEngineering #SoftwareArchitecture #SaaS
Staff+ Engineer in the SaaS World - The Control Planes
So far in our journey through the SaaS world, we’ve explored the multitenancy spectrum and the life of a tenant. Today we are going to broaden our view of the SaaS environment and explore control plan...
open.substack.com
April 9, 2025 at 1:38 PM
🚀 Staff+ Engineer in the SaaS World - The Control Planes 🚀
This week, as part our journey through the SaaS world, @tpeczek.bsky.social dives into the control planes.
🔗 open.substack.com/pub/pathfind...
#StaffEngineering #SoftwareArchitecture #SaaS
This week, as part our journey through the SaaS world, @tpeczek.bsky.social dives into the control planes.
🔗 open.substack.com/pub/pathfind...
#StaffEngineering #SoftwareArchitecture #SaaS
I watched Devil May Cry on Netflix in two evenings.
I really enjoyed it.
Highly recommended 😈
I really enjoyed it.
Highly recommended 😈
April 5, 2025 at 7:55 PM
I watched Devil May Cry on Netflix in two evenings.
I really enjoyed it.
Highly recommended 😈
I really enjoyed it.
Highly recommended 😈
Reposted by Tomasz Pęczek
how are we making a decision? whats the actual process of it? checkout my latest post on @pathfinder.engineer !
“Why did I assume that?!” 🤷♂️ We've all been there—jumping right past the facts straight to assumptions and misunderstandings.
🔗 pathfinderengineer.substack.com/p/why-we-jum...
#Growth #Communication #SelfImprovement
🔗 pathfinderengineer.substack.com/p/why-we-jum...
#Growth #Communication #SelfImprovement
why we jump to the wrong conclusions (and how to avoid it)
learning to use the ladder of inference in our personal and professional lives
pathfinderengineer.substack.com
March 27, 2025 at 1:33 PM
how are we making a decision? whats the actual process of it? checkout my latest post on @pathfinder.engineer !
In two weeks I'll be speaking at the SysOps/DevOps meetup in Kraków about "Zero Downtime Deployments for Azure PaaS-Based Applications".
If you're in the area, please feel invited 🙂.
If you're in the area, please feel invited 🙂.
March 20, 2025 at 10:52 AM
In two weeks I'll be speaking at the SysOps/DevOps meetup in Kraków about "Zero Downtime Deployments for Azure PaaS-Based Applications".
If you're in the area, please feel invited 🙂.
If you're in the area, please feel invited 🙂.
Reposted by Tomasz Pęczek
🚀 Staff+ Engineer in the SaaS World - The Life of a Tenant 🚀
Previously, @tpeczek.bsky.social explored the multitenancy spectrum. This week he continues the exploration and takes a look at the tenant lifecycle.
🔗 open.substack.com/pub/pathfind...
#StaffEngineering #SoftwareArchitecture #SaaS
Previously, @tpeczek.bsky.social explored the multitenancy spectrum. This week he continues the exploration and takes a look at the tenant lifecycle.
🔗 open.substack.com/pub/pathfind...
#StaffEngineering #SoftwareArchitecture #SaaS
Staff+ Engineer in the SaaS World - The Life of a Tenant
Previously in the “Staff+ Engineer in the SaaS World” we’ve been exploring the multitenancy spectrum. This article continues the exploration and looks at possible events in your tenant lifecycle.
open.substack.com
March 19, 2025 at 1:29 PM
🚀 Staff+ Engineer in the SaaS World - The Life of a Tenant 🚀
Previously, @tpeczek.bsky.social explored the multitenancy spectrum. This week he continues the exploration and takes a look at the tenant lifecycle.
🔗 open.substack.com/pub/pathfind...
#StaffEngineering #SoftwareArchitecture #SaaS
Previously, @tpeczek.bsky.social explored the multitenancy spectrum. This week he continues the exploration and takes a look at the tenant lifecycle.
🔗 open.substack.com/pub/pathfind...
#StaffEngineering #SoftwareArchitecture #SaaS
Reposted by Tomasz Pęczek
💣 Boom here comes the big news! I made the #ArchitectureWeekly a fully free newsletter. Yes, all the past articles and videos are free. Why did I do it?
www.architecture-weekly.com/p/whole-arch...
I believe that all of that gives you more content than a lot of books or paid online courses.
1/
www.architecture-weekly.com/p/whole-arch...
I believe that all of that gives you more content than a lot of books or paid online courses.
1/
Whole Architecture Weekly content is free now!
💣 Boom here comes the big news! The only constant in the world is change. I made the Architecture Weekly a fully free newsletter. Yes, that also include all the past articles and videos free. Why did ...
www.architecture-weekly.com
March 17, 2025 at 8:27 AM
💣 Boom here comes the big news! I made the #ArchitectureWeekly a fully free newsletter. Yes, all the past articles and videos are free. Why did I do it?
www.architecture-weekly.com/p/whole-arch...
I believe that all of that gives you more content than a lot of books or paid online courses.
1/
www.architecture-weekly.com/p/whole-arch...
I believe that all of that gives you more content than a lot of books or paid online courses.
1/
In two weeks' time, I'll be sharing my knowledge on "Implementing DevOps Practices for Azure Infrastructure" at Azure Day Poland 2025 in Warsaw.
If you're interested in attending (in person), there's a promo code I can share ( you can register at azureday.pl ): AzureDay2025Speaker
If you're interested in attending (in person), there's a promo code I can share ( you can register at azureday.pl ): AzureDay2025Speaker
February 28, 2025 at 12:29 PM
In two weeks' time, I'll be sharing my knowledge on "Implementing DevOps Practices for Azure Infrastructure" at Azure Day Poland 2025 in Warsaw.
If you're interested in attending (in person), there's a promo code I can share ( you can register at azureday.pl ): AzureDay2025Speaker
If you're interested in attending (in person), there's a promo code I can share ( you can register at azureday.pl ): AzureDay2025Speaker