Hi, my name is Kevin Simper. I work at GreenMobility as CTO and like to write about tech. I also like to make videos on youtube about programming and organize meetups.

My latest posts:

Bun is the new leap forward in TypeScript

Bun version 1 has just been released and it looks like it is going to be the new default runtime for TypeScript.

Bun takes a lot of best practices and oppinonated choices and brings them into one package, that is everything from hot reloading, testing, module loading, package managing and on top being crazy fast.

It has been pretty crazy to follow how quickly they have been able to match Node.js features 1-to-1 in basically under 1 year. They have also within the last couple of months made all the popular libraries like Next.js and Prisma work in Bun.

Node.js is fast thanks to Chrome V8 JavaScript Engine, and I think many had gotten the idea that there was not much more perforamance to gain further, as V8 "probrably" was as optimized as it could.

Read full post
2023-09-10

    How I do data analytics with BigQuery

    I use BigQuery at GreenMobility for all our reports. All our reporting on our finance, to data analytics how how our vehicles is used, to calculating user segments and LTV (Life Time Value). I have also used it for two years for generating our version of Spotify Wrapped.

    BigQuery is phenominal because all queries only takes seconds. It is nearly impossible to make a slow query and you do not need to care about indexes or if you query does a full table scan. For example the query for generating GreenMobility Wrapped takes only 15 seconds and it queries 7 tables and a year of data.

    BigQuery SQL compared to Postgres SQL is close, but they are different enough that switching between them is a inconvenience. BigQuery for example does not do implicit conversion, it is more type strong and can not compare Dates to Timestamps for example.

    Read full post

    Documentary about the creation of React.js

    Watching this documentary brings up a lot of fun memories, it was as crazy as they talked about and the people in it are also really likeable, I think that is also visible. Dan Abramov, Christopher “vjuex” Chedeau, Sophie Alpert, Pete Hunt. Watch it if you want to see how React.js really felt at the start and not just how it feels today as all we only does 😄

    Read full post
    2023-02-28

      Create videos with React.js

      I have been making videos with Adobe Premiere and dabbled with After Effects for few animations, but it is so far from coding and requires a lot of knowledge.

      Read full post
      2023-02-22

        How to structure a http route

        I want to go over in this post how to structure a http route so that it becomes maintainable. Everything small is maintainable and everything starts out simple, but the real value comes when things are changed and adapter to become smarter and quicker for the users. So making a program easy to change is more important than easy to write the first time.

        A good example of a complicated route is signup. A good signup consists of:

        1. validating the users input
        2. checking if the user exists
        3. creating the user

        Quick estimate that would be 50 lines of code. Let us try to make it here:

        Read full post