Luke Merrett

Luke Merrett

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PyCon UK 2023 Raw Notes

PyCon UK 2023 Raw Notes

Notes on this year's PyCon UK conference held in Cardiff: talk highlights, quotes & thoughts.

Building C4 Diagrams in Mermaid

Building C4 Diagrams in Mermaid

Using MermaidJS to render C4 Diagrams in Markdown

Mermaid Diagrams as Code in Notion

Mermaid Diagrams as Code in Notion

How to display lovely diagrams in Notion using Mermaid syntax

When a Flask DB Upgrade Fails on a Batch of Scripts

When a Flask DB Upgrade Fails on a Batch of Scripts

What happens when 1 script in a "flask db upgrade" batch fails, how does the roll back behave?

A Dive into Python Type Hints

A Dive into Python Type Hints

An overview of typing hinting in Python, including Optional, Union, Protocol, TypeVar and Callable types.

Different Merge Types in Git

Different Merge Types in Git

Demystifying the difference between "Merge", "Fast Forward Merge", "Squash and Merge" and "Rebase and Merge" on Git

C4, Diagrams as Code & Architectural Joy

C4, Diagrams as Code & Architectural Joy

This is a long form article showing the journey of how we gained value in using C4 diagrams combined with Diagrams as Code when representing our team's architecture. I wanted to go into detail about where we were coming from and the issues we saw in that approach,

Record Types in C# 9.0

Record Types in C# 9.0

What are Record Types? Record Types are a popular feature of F# [https://docs.microsoft.com/en-us/dotnet/fsharp/language-reference/records], also commonly found in other functional languages, that have recently been introduced to C# in version 9.0 [https://devblogs.microsoft.com/dotnet/c-9-0-on-the-record/] (released alongside .Net 5). On

Getting Things Done in Notion Using Tables

Getting Things Done in Notion Using Tables

One of the key draws of Notion [https://www.notion.so/] is the flexibility its Table functionality brings, acting as a combination of Trello, MS Access & a To-Do-List all in one. Using this tool you can set up relatively complex workflows across multiple views. To show off this feature

Building a Personal Highlights Tracker in Notion

Notion [https://www.notion.so] is a relatively new wiki tool that's been gaining a lot of traction lately, especially with task management geeks like myself. You can think of it initially like a web-based wiki (with desktop & mobile apps), it has a hierarchy of pages you

Automating Pilot Health Checks with Holt-Winters & Graphite

Automating Pilot Health Checks with Holt-Winters & Graphite

Recently Netflix announced the release of Kayenta [https://medium.com/netflix-techblog/automated-canary-analysis-at-netflix-with-kayenta-3260bc7acc69] ; an open source tool for automating canary analysis they use to ensure their pilot deployments are healthy. This post outlines how you can achieve something similar with built-in Graphite functionality; we will set up a test server in

Deploying Docker Containers with Azure Container Instances

Deploying Docker Containers with Azure Container Instances

For one of my upcoming blogposts I have been exploring options for hosting Docker containers in the cloud. Along the way I found that Azure Container Instances is a relatively straight foward, no nonsense approach if you're after rapidly hosting an image without having to deal with the

Timing a Function in F#

This can be useful for capturing how long an operation takes to execute, it also nicely demonstrates how generics operate in F#. Modified from the original version found in the F# Programming Wikibook [https://en.wikibooks.org/wiki/F_Sharp_Programming/Higher_Order_Functions#A_Timer_Function] open System.Diagnostics

Environment Specific Configuration in DotNet Core

Environment Specific Configuration in DotNet Core

It's common to have different application configurations per environment (e.g: Dev, QA, Production) allowing us to switch between them at each stage. In older Web Applications this was usually done with Web Config Transformations or Razor files, however the new ConfigurationBuilder available in DotNet Core makes it

F# Data Type Providers in .Net Core

F# Data Type Providers in .Net Core

As one of F#'s killer features; type providers have the ability to make rooms full of developers gasp when shown for the first time. Support has recently been added to the FSharp.Data library [https://www.nuget.org/packages/FSharp.Data] for .Net Standard 2.0, allowing us

Behaviour Driven Unit Tests

Behaviour Driven Unit Tests

> "If we change the implementation details, none of our tests should break" - Ian Cooper This blog comes following a work chat around one of the best tech talks I've watched; TDD: Where Did It All Go Wrong [https://vimeo.com/68375232] by Ian Cooper

Using Pomodoro Day To Day

Using Pomodoro Day To Day

The Pomodoro Technique [http://cirillocompany.de/pages/pomodoro-technique] is one of my favourite "life hacks" for increasing your focus & productivity and is one, as a programmer, I've used frequently across my last 3 jobs to great effect. I wanted to post an article focusing not

Removing Mistakes With Git Rebase

Removing Mistakes With Git Rebase

Let's say you've got a public repository on GitHub where you're building a basic website hosted on AWS. Part of your website accesses an AWS service like S3, DynamoDB or SQS, so naturally you may have your AWS access key and secret stored in

Getting Started With Pico-8

Getting Started With Pico-8

Pico-8 is a fantasy console [http://www.lexaloffle.com/pico-8.php] recently featured in a Humble Bundle [https://www.humblebundle.com/overwhelmingly-positive-bundle] pack on game development. What do the developers mean by "Fantasy Console"? Well think of it like a NES Emulator that also provides all the tools

F# on AWS Lambda

F# on AWS Lambda

On the 1st December AWS announced support for C# in AWS Lambda [https://aws.amazon.com/blogs/compute/announcing-c-sharp-support-for-aws-lambda/] which is, by all accounts, great news! However being a bit of an F# fanatic I wondered if, as it does support .Net Core, we could host an F# project as

Let's Play with Azure Functions

Let's Play with Azure Functions

I saw a great talk last night at F# |> Bristol [https://www.meetup.com/FSharpBristol/] by Anthony Brown on how to use Microsoft Azure and F# to build a search engine (full talk here [https://skillsmatter.com/skillscasts/8901-f-sharpunctional-londoners-meetup]). The talk incorporated Azure Web Jobs, Azure Search, Resource Manager

Binary Search Tree in F#

Binary Search Tree in F#

Having a focus on Software Engineering over core Computer Science concepts; my algorithm-fu is not what it should be! Thankfully there are plenty of books out there and my recent focus on functional programming in F# is helping alleviate that. This weekend I learned how to build a Binary Search

Getting Started with ElasticSearch

Getting Started with ElasticSearch

We're currently focusing on improving our ELK (Elasticsearch, Logstash & Kibana) monitoring service & the reporting around error levels. This has given me the perfect opportunity to learn a bit more about Elasticsearch and play about with it's rest apis. Elasticsearch [https://www.elastic.co/products/

F# Domain Modelling

Over the last few weeks my team and I have been setting up a new QA environment to validate a rather large piece of ongoing work. As part of this I thought it would be prudent to automate our health checks so we can ensure the environment has launched successfully

Getting Started with Docker and NodeJS

I've wanted to play with Docker for a while and, with the Docker Toolbox, this is becoming easier over time for Windows based degenerates like me. Docker allows us to seperate services from the host operating system in small, self contained packages that are not coupled to the