Mikael Henriksson

Senior Software Developer and Designer

mikael@mhenrixon.com

github.com/mhenrixon

mhenrixon.com

+49 173 572 85 24

linkedin.com/in/mhenrixon

Skills

Languages:
Ruby, Lua, JavaScript, HTML, CSS, SQL, pSQL, ShellScript (bash fish)
Frameworks:
Ruby on Rails, RSpec, Sidekiq, Hotwired, Turbo, PostgreSQL, StimulusJS, TailwindCSS
Databases:
Redis, PostgreSQL, MySQL, MariaDB
Tools:
Docker, git, GitHub, Dokku, Terminal, Continuous Integration

Projects

Sidekiq Unique Jobs github.com/mhenrixon/sidekiq-unique-jobs

Ruby, Redis, Lua, Sidekiq

  • Prevents duplicate sidekiq job with a fancy redlock mechanism
  • Uses Lua scripts for performance
  • Been supporting it since July, 2012 when I extracted it from Sidekiq
  • Object oriented code base that is a pleasure to work with
Yoga Durgaya https://yogadurgaya.de

Ruby, Ruby on Rails, TailwindCSS, Stimulus, Hotwire, Turbo

  • A simple website for yogadurgaya

Experience

HL Design & Media AB, Växjö, Sweden
2022 - Current
Remote (Employment) Senior Fullstack Developer
  • Upgrading Ruby on Rails from 4.1 to 6.1
  • Performance improvements across the entire stack.
  • ERP system integrations with Fortnox, Pyramid Pro Client.
  • Integrated with Klarna Settlements.
  • Reduced memory usage with 60+ percent by switching to Jemalloc.
  • Parallelization of background jobs.
  • Implemented monitoring and APM using AppSignal.
  • Reduced page load times by setting up cloudfront distributions for both rails assets and Amazon S3.
Pitchfish Inc, Richardson, TX, USA
2021 - Current
Remote (Founder) Senior Fullstack Developer
  • Greenfield rails 7.0 project using all the new rails technologies
  • Implemented design using TailwindCSS 3.0, Stimulus JS and Ruby on Rails 7.0 and the latest hotwire and turbo-rails for partial page updates.
  • Built all the initial frontend using aforementioned technologies and created a UX framework onto of TailwindCSS 3.0
  • Inbound and outgoing emails implementation using Postmark
  • Payment integration with Stripe Connect for buyers to reimburse them for their time
  • Payment integration with Stripe Checkout Express to allow sellers to put the money down for a pitch.
  • PostgreSQL for database
  • Redis and Sidekiq for background job processing
Nalantis, Belgium, Antwerp
2021 - Current
Remote (Contract) Senior Fullstack Developer
  • Greenfield rails 7.0 project using all the new rails technologies
  • Implemented design using TailwindCSS 3.0, Stimulus JS and Ruby on Rails 7.0 and the latest hotwire and turbo-rails for partial page updates.
  • Built all the initial frontend using aforementioned technologies and created a UX framework onto of TailwindCSS 3.0
mhenrixon Consulting, Blankenburg (Harz), Germany
2018 - Current
Remote (Founder) Senior Backend Developer
  • See all the various remote freelancing roles during this time period
Joint Academy, Malmö, Sweden
2020 - 2021
Remote (Contract) Senior Backend Developer
  • Upgraded the monolith to Rails 6.1.
  • Implemented backend for video calls, scheduled calls and call center functionality for the US market using Twilio.
  • Implemented custom state machines for video calls
  • Upgraded ruby from 2.6.1 to 2.7.2
  • Upgraded all the hundreds of other dependencies (ruby gems) in the monolith
  • Reduced production docker image size from 1,6 GB to 395 MB
  • Dockerized development environment, sprinkling that little Makefile magic on top of docker.
  • Improved test suite performance (inside docker) from 80+ minutes to ~12 minutes
  • Designed and built out an event-driven micro service architecture template with RabbitMQ for messages.
Wundertax Gmbh, Berlin, Germany
2020 - 2020
Remote (Contract) Fullstack Developer
  • Instrumental in migrating all ruby services from Gitlab, CircleCI and DEIS to GitlabCI and Kubor/ Kubernetes.
  • Implemented various new rules for the tax year 2019
  • Streamlined the development environment for all services using Docker with a little Makefile magic to create some external dependencies
  • Extracted core business logic from ruby gems and monolith into several new rails services
  • Improved testing reliability and code coverage
  • Upgraded all services to Rails 6.1 and Ruby 2.7.2
solarisBank AG, Berlin, Germany
2018 - 2019
Remote (Contract) Senior Backend Developer
  • Extracted person identifications from monolith into new service
  • Migrated to new person identifications service with close to zero downtime
  • Developed core functionality on PSD2 initiative (open banking)
  • Developed partner invoicing for person identifications
  • Developed customised signing endpoint
ProSiebenSat.1, Munich, Germany
2018 - 2018
Remote (Contract) Senior Backend Developer
  • Stabilisation of all systems
  • Developing structured logging
  • Setting up continuous integration
  • Setting up continuous delivery
  • Standardisation of processes
  • Rolled out a mongodb cluster
  • Developed an automated mongodb backup system
solarisBank AG, Berlin, Germany
2017 - 2018
Remote (Contract) Senior Backend Developer
  • Part of building a fully autonomous agile team.
  • Contributed greatly in overall improvements of everything from how docker is used to improving build times, test times, reliability of tests to how the team worked together.
  • Developed a service to handle data change requests (part of the core banking offering).
  • Developed a feature flags solution.
  • Developed an IBAN lookup and validation service.
  • Developed a service for screening people for PEP hits.
  • Developed functionality for statement of accounts.
  • Developed functionality for bank statements.
  • Developed functionality for standing orders.
  • Developed functionality for dealing with account limits.
Zoolutions AB,, Landsbro, Sweden
2007 - 2018
Remote (Founder) Senior Backend Developer
  • See all the various remote freelancing roles during this time period
Reevoo Ltd, London, England
2016 - 2017
Remote (Contract) Senior Backend Developer
  • Performance and scalability improvements to the systems that handle grouping of product reviews
  • Designed and implemented a logging, monitoring and alerting system for standardized logging (See https://github.com/reevoo/sapience-rb for more info)
Kisko Labs, Helsinki, Finland
2014 - 2017
Remote (Contract) Fullstack Developer
  • Implemented recurring card payments for PRO Accounts with Stripe
  • Ongoing performance optimizations
  • Upgraded Ruby on Rails from 3.2 to 4.2
  • Implemented Gym membership billing with Stripe
Cubits, Berlin, Germany
2016 - 2016
Onsite (Employment) Senior Backend Developer
  • Integrations with third party payment systems.
Crealytics GmbH, Berlin, Germany
2015 - 2016
Onsite (Employment) Senior Backend Developer
  • Improved Continuous Delivery by creating a true pipeline using Jenkins and Jenkins Workflow
  • Designed and implemented a Message Bus using Kafka on Apache Mesos
  • Improved the local workflow with docker-compose
  • Implemented NewRelic monitoring for all microservices recording cross application transactions
  • Designed a reverse proxy/api gateway using Kong
  • Designed the backend implementation of an activity feed
Hero Gaming AB, Malmö, Sweden
2013 - 2015
Remote (Contract) Senior Backend Developer
  • Designed and implemented payment transactional system; a scalable design created with the intent that newer and less experienced developers could access and change without effecting performance or extendability
  • Automated server provisioning using chef
  • Developed full test coverage for server configuration for both unit and integration tests
  • Optimized CasinoSaga API to serve up to 2500 requests per minute on a single physical host
  • Optimized the seamless wallet servers to respond in average 100-200ms per money transaction
  • Developed API integrations from AngularJS to said API
  • Developed integrations with gaming providers in AngularJS
Form26 Ltd, Richardson, TX, USA
2011 - 2014
Remote (Founder) Fullstack Developer
  • Created http://taskk.it using Ruby on Rails, PostgreSQL a program that automatically fills allotted “time to spend on tasks” based on custom algorithms (patent pending)
  • Created http://wodstack.com using Ruby on Rails, PostgreSQL and and Elastic Search. WODstack was later sold to a Finnish company (Kisko Labs) and all customers migrated to WODconnect http:// www.wodconnect.com
HL Design & Media AB, Växjö, Sweden
2012 - 2013
Remote (Employment) Senior Fullstack Developer
  • Developed a highly scalable localization backend for the flagship WM3
  • Optimized server processing times approximately 75% for WM3
  • Developed a widget based intranet using AngularJS
Arne Johanssons Fastighetsservice AB, Lammhult, Sweden
2007 - 2013
Remote (Contract) Fullstack Developer
  • Designed and developed an invoice management system using .NET 2, NHibernate and SQL Reporting Services for BI and invoice generation, installed on customer’s private machine running in UltiDev Cassini Web Server
Evry One, Växjö, Sweden
2011 - 2012
Remote (Employment) Senior Software Developer
  • System developer on Jeeves
  • Developed a mobile web application for internet explorer mobile / windows ce 5
  • Onsite SQL performance optimizations for customer located in central Manhattan, New York
Play'n GO, Växjö, Sweden
2010 - 2011
Remote (Employment) Senior Software Developer
  • Developed a Ruby-on-Rails e-commerce system for Opticians reseller with focus on ease of use for placing orders
  • Designed and developed a security system for a Windows Form app with corresponding WCF service
  • Integrated payment solutions and game providers into existing backend system to provide PNG’s customers required payment options
  • Upgraded existing web application to .NET 4, NHibernate 3, and MVC 3
  • Developed an integration with ATG into existing backend systems
  • Set up continuous integration environment with possibility of 1-click deployments and upgraded to .NET 4.0
  • Developed payment and shipping modules for a PHP e-commerce application
  • Managed various required upgrades and major maintenance tasks for proper scalability
  • Designed SMS billing application to build away errors from current system
  • Created a 3-tier subscription based app for mobile applications and web applications
Numo Solutions AS, Oslo, Norway
2008 - 2010
Onsite (Employment) Senior Software Developer
  • Substitute CTO / Tech Lead (February – May 2009) of a company rebranding project
  • Designed and developed billing system, a CMS for mobile web, and upgraded core projects from .NET1,0 to .NET 3.5, and a highly scalable enterprise contact backup system
  • Migrating/upgrading the production database from MS SQL Server 2005 to MS SQL 2008 to make use of CDC to push data to a separate reporting environment
C. Gunnarssons Verkstads AB, Vislanda, Sweden
2007 - 2008
Remote (Employment) Software Developer
  • System design and development when upgrading one of CGV’s old customers from using a VB6 application to control their saw mill to use a new .NET app with thin clients running a remote app on a Windows 2008 Server instance
Wadley Enterprises, Brisbane, Australia
2005 - 2007
Onsite (Employment) Fullstack Developer
  • Design and developed an online based purchase order system
  • Designed and developed a try & buy webshop for the system
  • Automated deployment for the customer at sign up
  • Creation of website, database, and an initial company/department and admin user