Systems Programming

Richard Carlsson

Consultant, Happi Hacking AB


Richard is one of the world’s most experienced Erlang developers. He has been programming in Erlang since 1994 as a masters’ student, as a Ph.D. student in the High Performance Erlang research group at Uppsala University, and as a senior developer at Klarna.

Richard has contributed to many parts of the Erlang standard libraries, compiler, runtime system, and the language itself, and he is co-author of the book ”Erlang and OTP in Action”. He has written several well-known open source tools, including the unit testing framework EUnit and the documentation tool EDoc which are used by most Erlang programmers.

He was one of the earliest employed programmers at Klarna and worked there for 11 years, mainly on handling the explosive growth from a dozen to over a hundred developers, and a hundred times more code, while the system maintained availability around the clock and was being updated daily.

Richard has presented his work at many academical conferences and workshops and received the ”Erlang User of the Year” award as a member of the HiPE research group. He has taught distributed programming and compilers at Uppsala University.

He had a vital role in the development of Simics DML (Device Modelling Language), now Wind River Simics DML. He has also worked on C compilers for both ARM and RFID chips, written floating point libraries in assembler, and has long experience of assembler programming for 8- and 16-bit micro processors.

Specialized in

Example Projects

December 2022 - April 2023 Cloud Provisioning, Happi Hacking AB

Remodelled the HappiHacking company cloud solutions using Infrastructure as Code.

Tools: AWS, Docker, Terraform, Ansible, bash, Make, git

May – December 2021 Frontend/Web Designer, Happi Hacking AB

Rebuilt the HappiHacking company web site from the bottom up using modern techniques for web development and design.

Tools: Eleventy, Nunjucks, JavaScript, CSS/SASS, SVG, HTML

March – April 2021 Java Developer, Major German Telecom operator

Prototyped an OAuth manager for connecting third party services to social platforms. (Part of a larger long term project around services for home automation.)

Tools: Java, Spring Boot, OAuth

2020 - 2021 Advisor and Compiler Developer, WhatsApp

Prototyping a strictly typed dialect of Erlang.

Tools: Erlang, Scala

Previous engagements

2019 - 2022 Founding Member, Erlang Ecosystem Foundation

2013 - 2019 Founding Member, Erlang Industrial User Group

2008 – 2019 Senior Developer and Architect, Klarna AB

Tools: Erlang, Git, Make, Bash, C, LevelDB, Svn

2006 – 2008 Compiler Developer, IAR Systems

Tools: C, C++, Ruby, Visual Studio, Subversion, Jira, CMake

2004 - 2005 Developer, Virtutech

Development and productification of Simics DML (Device Modeling Language), a domain specific extension of C for modelling hardware components. Virtutech was later bought by WindRiver/Intel.

Tools: Python, C

1998 - 2004 Ph. D. Student, Uppsala University

Tools: Erlang, C, Perl, LaTeX

Open Source Software



Education (by selection)

1998 – 2004 Postgraduate Student, Uppsala University

1990 – 1997 M.Sc. Mathematics and Natural Science, Uppsala University