John Hamelink

ABOUT ME

Great communicator: Elixir, Ruby, Rails, Docker, Kubernetes with 15+ years experience

In the past I completed over 130 sessions on Codementor.io!

I'm a consultant developer who's been coding for almost 20 years now: 15 of those years professionally. I mainly work in Rails, Elixir and Typescript these days, but I've built things in languages like Go, PHP, Python, and Perl. I also write a lot of Emacs lisp for fun, since I use Emacs as my editor. I've had the opportunity to have large multi-nationals on my personal client list such as Mozilla, IBM, 888.com, Tennents Larger (C&C Group plc) and multiple large financial businesses. I've also done consulting for Sequoia Capital, The European Commission, and

Outside of Freelancing, I'm currently working as a contractor for a startup based in England. In the past I've operated as an employee for agencies and product companies, as well as co-founding small-stage startups with others, some of which were successful enough that I was able to sell equity.

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Joined April 2014

EXPERTISE

Ruby

10 years experience | 19 endorsements

I use Rails every day to build complex apps for my clients. I have experience building completely Test Driven apps (using TDD principals)...

I use Rails every day to build complex apps for my clients. I have experience building completely Test Driven apps (using TDD principals). I use continuous integration to enforce testing within my own company.

RSpec Grape Aasm Devise Heroku Pry

Ruby on Rails

10 years experience | 27 endorsements

I use Rails every day to build complex apps for my clients. I have experience building completely Test Driven apps (using TDD principals)...

Pry RSpec Grape

Pry RSpec Grape Aasm Devise Heroku

Grape

9 years experience

I've built 5 APIs that are in production and have been maintained through multiple major revisions. I can help you understand how to buil...

I've built 5 APIs that are in production and have been maintained through multiple major revisions. I can help you understand how to build maintainable, scalable APIs in ruby using Grape, as well as share some snippets I use to help DRY up my code when building APIs.

Grape Hash Ruby

Grape Hash Ruby Ruby on Rails Grape api

Kubernetes

6 years experience

I've built three production-grade clusters for three different projects: using helm to produce multiple environments and linking into CI/...

I've built three production-grade clusters for three different projects: using helm to produce multiple environments and linking into CI/CD pipelines, as well as using ServiceBroker to handle databases and other resources outside of k8s.

Azure Continuous Deployment Continuous Integration

Azure Continuous Deployment Continuous Integration Containers Docker AWS

Elixir

7 years experience

I've built 3 production-grade APIs and one (simple, small budget) social media platform since February 2016. Some open source Elixir lib...

I've built 3 production-grade APIs and one (simple, small budget) social media platform since February 2016. Some open source Elixir libraries I've written so far: https://github.com/johnhamelink/xslt https://github.com/johnhamelink/sms_blitz https://github.com/johnhamelink/mws https://github.com/johnhamelink/exrm_deb

Phoenix Ecto Elixir

Phoenix

7 years experience

I actively work on an API which handles 60,000 active users a day and makes heavy use of Ejabberd for chat. I've built a multi-lingual C...

I actively work on an API which handles 60,000 active users a day and makes heavy use of Ejabberd for chat. I've built a multi-lingual CMS for a mobile app which is in the top-10 list on Apple's App Store. i've built a simple social network using Neo4J as a graph database. I built a photo moderation system which was used within a video transcoding pipeline to produce tens of thousands of custom videos for an app which promoted a popular music festival in Scotland (T in the Park).

Phoenix Jabber ejabberd

Phoenix Jabber ejabberd Ecto

PostgreSQL

11 years experience | 4 endorsements

Exeprience with use of Postgres at scale, including using RDS, JSONB, Hstore, PostGIS, even custom extensions!

Database Schema SQL Database

Database Schema SQL Database PostgreSQL Postgres hstore PostGIS Relational Database

SOCIAL PRESENCE