Month: November 2021

Useful Stuff I Read This Week

Here are 7 posts I thought were worth sharing this week.

This is an amazing read. Etsy engineer Salem Hilal shares their ES6 to Typescript journey. In this post, he covers the strategy, technical challenges they faced, tooling they built, and how they educated their engineers to write effective Typescript code. Etsy has been built over the last 16 years and they had 17000 JS files. Migrating such a codebase is a multi year effort. You need to have a clear plan and ensure there are no tail migration issues. 

A couple of months back a customer wanted us to migrate their 20+ TB Oracle database to Postgres. They had hundreds of stored procedures written in Oracle. Also, their batch processing jobs were written in stored procedures. They wanted to do the complete migration in a couple of months. We politely told them it is not possible. They went with another vendor that said they could do it in two months. Migrations are very risky. There are so many unknowns involved. For a vendor it is much more difficult because they don’t even understand your functional requirements and code base. For migrations I prefer to be safe than sorry.

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Understanding Little’s Law

Little’s law states that the long-term average number L of customers in a stationary system is equal to the long-term average effective arrival rate λ multiplied by the average time W that a customer spends in the system.

{\displaystyle L=\lambda W.}

Where

L = Average number of customers in a stationary system
λ = Average arrival rate in the system
W = Average time a customer spend in the system

In context of an API it means:
L = Average number of concurrent requests system can serve
λ = Average arrival rate of requests in the system
W = Average latency of each request

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Useful Stuff I Read This Week

Here are 11 posts I thought were worth sharing this week.

I like the idea of learning a new language by reading its standard library. You learn the idiomatic way of writing code in a language by reading source code written by its original authors. I am planning to learn Rust. I will also give this approach a try. There are two limiting factors when you might struggle with this approach 1) Poor documentation 2) when the standard library is implemented in a lower level language.  

Author of the post shares his views on important features he expects from a future scripting language. I agree with his list. I will add a couple more:

  • Better tooling support. Author talked about IDE but I think tools for formatting, packaging, scaffolding, new modules, etc should also be part of the language standard tooling. 
  • Simple. It should have one idiomatic way to do a task. Also, stability should be preferred over feature bloat. 
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