John Hamelink

John Hamelink

Mentor
4.9
(101 reviews)
US$29.99
For every 15 mins
134
Sessions/Jobs
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First 15 mins free for your first session
ABOUT ME
Great communicator: Elixir, Ruby, Rails, Docker, Kubernetes with 15+ years experience
Great communicator: Elixir, Ruby, Rails, Docker, Kubernetes with 15+ years experience

I've now completed over 130 sessions on Codementor!

I'm a consultant developer who's been coding for over 10 years now; 6 of those years professionally. I mainly work in Rails and Elixir these days, but I've built things in languages ranging from C to NodeJS to Go. 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 Codementor, I'm a senior engineer at a well-funded financial-tech company based in England. In the past I've operated as a self-employed consultant, as well as co-founding small-stage startups with others, some of which were successful enough that I was able to sell equity.

English
Edinburgh (+01:00)
Joined April 2014
EXPERTISE
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.
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)...
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.
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.
GrapeHashRuby
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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.
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
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).
11 years experience | 4 endorsements
Exeprience with use of Postgres at scale, including using RDS, JSONB, Hstore, PostGIS, even custom extensions!
Exeprience with use of Postgres at scale, including using RDS, JSONB, Hstore, PostGIS, even custom extensions!

REVIEWS FROM CLIENTS

4.9
(101 reviews)
Derek
Derek
May 2018
Very knowledgeable!
Joseph M. Sak
Joseph M. Sak
April 2018
Very friendly, knowledgeable, helped me greatly by being a second pair of eyes on the problem!
Amechi Egbe
Amechi Egbe
March 2018
John was absolutely swift and amazing in helping me solve my issue! I will definitely be using John again for future work!
Eddie Sitt
Eddie Sitt
June 2017
Amazing mentor, really helped a lot!! would definitely recommend
Jack Zerby
Jack Zerby
October 2016
He's the best on Codementor by FAR!
Hans K
Hans K
October 2016
John was very helpful in establishing the way to properly test/debug a not-straightforward deployment of a feature
Vadim Sokoltsov
Vadim Sokoltsov
October 2016
He doesn't have a huge experience in field area, that needed me, but I received some useful advises and next time when something goes wrong with my project I'll call him.
Samuel Smith
Samuel Smith
October 2016
Very quickly understood my problem despite my poor attempt to explain it. Great service.
Matt
Matt
September 2016
Brilliant as usual. Very knowledgeable. Always great to work with.
Jack Zerby
Jack Zerby
September 2016
John was able to jump in and help me solve my problem right away, quickly and efficiently. HIGHLY recommend!
SOCIAL PRESENCE
GitHub
exrm_deb
Create a deb for your elixir release with ease
Elixir
73
12
ansible-kibana-elasticsearch-logstash-logstash-forwarder
Ansible roles for Kibana, Elasticsearch, Logstash, and Logstash-forwarder
19
1
Stack Overflow
582 Reputation
0
11
25