My name is Lucas Mendelowski and I’m software engineer focused on building web applications from Krakow, Poland. I mostly work with Ruby (on and off the Rails) and JavaScript / TypeScript (with React and Ember.js).

This website is my knowledge base of all the things I learned across a variety of languages and technologies.

Latest posts

2023-03-07 - Update head content from Phoenix layout
2023-02-02 - Prepared statements in PostgreSQL
2023-01-24 - Declaring flags with iota in Go
2023-01-09 - Pointer vs Value receiver on Go interface
2023-01-04 - Array vs Slice in Go
2022-10-06 - Exit GenServer registered with name
2022-09-18 - CORS, CSRF and WebSockets
2022-09-05 - Customize params in Phoenix links
2022-08-16 - Adding custom arguments to Phoenix controller's actions
2022-07-25 - Ecto cheatsheet 101
2022-07-19 - Lesser known Rails 7 features
2022-06-05 - Installing pg_gem with Bundler on Mac M1
2022-02-06 - Module prepend and alias method in Ruby
2022-01-21 - Accessing method name and its arguments at runtime in Ruby
2022-01-19 - Destructuring lists with various number of elements in Elixir
2022-01-04 - Code points to binaries in Elixir
2021-11-07 - Calling Ruby method from specific ancestors
2021-10-04 - Removing event from fullcalendar with React by dragging out
2021-08-08 - Installing Epson L3060 scanner on Linux
2021-06-27 - Instrumenting block of code with ActiveSupport::Notifications
2021-06-06 - React children props with TypeScript
2021-05-23 - Importing images with Webpacker
2021-04-25 - Rails compatible model with rom-rb
2021-04-11 - Finding most recent children for a record in PostgreSQL
2021-04-04 - Update primary key with foreign constraints
2021-03-21 - Change screenshots path for Gnome
2021-03-07 - Fork a subdirectory of a git repo
2021-02-14 - Recursive SQL queries with PostgreSQL
2021-02-07 - Reusing Rails scopes in the OR operator
2021-01-31 - Email previews with Rails
2021-01-02 - Simple HTTP server with Ruby
2020-12-20 - Spell checking in VIM
2020-12-13 - Rails query cache
2020-11-29 - Nested transactions with Rails
2020-11-22 - Generic result type in Go2
2020-11-15 - Turning string into predicate in Ruby
2020-11-08 - Locating code changes in git repo
2020-11-01 - Using auto-loaded constants in Rails initializers
2020-10-18 - Current directory of aliased script in bash
2020-10-11 - Override new method for creating subclasses in Ruby
2020-10-04 - Limit with ties in PostgreSQL
2020-09-27 - Sleep screen from terminal on Linux
2020-09-20 - New way for arguments forwarding in Ruby 2.7
2020-09-13 - Deprecating methods with ActiveSupport
2020-09-06 - Natural join in SQL
2020-08-29 - Benchmarking Ruby code
2020-08-23 - Accessing database configuration with Rails
2020-08-16 - New methods introduced in Ruby 2.7
2020-08-09 - Pattern matching with Ruby
2020-08-03 - Rails database migrations cheat-sheet
2020-07-19 - Dynamic layouts in Ember.js
2020-07-12 - Template pattern
2020-07-05 - Adding Bulma to Ember.js application
2020-06-28 - Prettifying Ember.js codebase
2020-06-21 - Create sudo user on Linux
2020-06-08 - Authentication for private Ruby gems
2020-05-31 - Running tests with Minitest
2020-05-24 - Grep files for content
2020-05-17 - Dates overlapping with PostgreSQL
2020-05-10 - Installing mysql2 gem without MySQL on MacOS
2020-05-03 - Super and dynamically created methods in Ruby
2020-04-26 - UFW setup
2020-04-19 - Tig - cheat sheet
2020-04-12 - Running commands concurrently with bash
2020-04-05 - Text search with PostgreSQL
2020-03-22 - Remove merged branches from git remote
2020-03-15 - Nginx - developer cheat sheet
2020-03-08 - Search and navigation cheat sheet for VIM
2020-02-29 - Padding numbers with zeros in Ruby
2020-02-23 - Enumerable#tally in Ruby 2.7
2020-02-16 - Group by JSONB array in PostgreSQL
2020-02-01 - Upsert in PostgreSQL
2020-01-26 - ROLLUP and CUBE with PostgreSQL
2020-01-19 - Aggregate functions over partition in PostgreSQL
2020-01-11 - Pivot functions in PostgreSQL
2019-12-31 - Conditional joins with Hanami
2019-12-26 - :wq vs :x in VIM
2019-11-07 - Moving data from database column to jsonb field
2019-08-26 - HSTS with Rails
2019-08-25 - Handling DOM events with Ember
2019-08-10 - Order of model associations in Rails
2019-08-03 - Array.wrap vs Kernel#array
2019-08-02 - Redirect back with Rails
2019-04-30 - Overriding model name in Rails
2019-04-07 - Method aliasing with Ruby
2019-03-23 - Using OR operator with Hanami repositories
2019-03-12 - Preloading subset of association with Hanami
2019-02-22 - Attaching custom behavior to Ember changesets
2019-02-15 - Undoing a Git rebase
2019-01-07 - Run gofmt on all project files
2018-12-24 - Using PostgreSQL enums with Ruby on Rails
2018-12-20 - Using PostgreSQL hstore with Ruby on Rails
2018-12-04 - Running multiple PostgreSQL versions on MacOS
2018-07-30 - self vs extend self vs module_function
2018-02-17 - Refs in React
2017-12-10 - Using libraries from NPM Ember