Profile

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

• Compilers
• Domain Specific Languages
• Virtual Machines
• Parsers
• State Machines
• Static Analysis
• Refactoring
• Modernizing Legacy Code
• Version Control
• Build Systems

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

• Developed a domain specific language that became the foundation of the credit assessment system.
• Developed a system of hierarchical state machines for specifying time-based events on invoices.
• Developed a system for heuristic matching of addresses.
• Restructured the system to allow many teams to work on the code in parallel.
• Rewrote the build system for faster and fully parallelized builds.
• Drove the transition to package-based code deployment.
• Drove the adoption av LevelDB as database backend.
• Submitted many upstream patches to Erlang/OTP.
• Handled the transition from Subversion to Git.
• Managed Open Source questions.
• Erlang community contact person.
• Company representative in the Erlang Industrial User Group and founding member of the Erlang Ecosystem Foundation.

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

2006 – 2008 Compiler Developer, IAR Systems

• Code generation and floating-point library routines for RFID chips.
• Led the transition to modern systems for version control and issue tracking, developer tooling, and automated builds and backups.

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

• Partial evaluation and inlining of Erlang programs.
• Abstraction of syntax trees and source code level transformations.
• Design and specification of Core Erlang.
• Data flow analysis, control flow analysis and type analysis on Core Erlang.
• Teaching: distributed programming, compilers, and object oriented programming in Java.

Tools: Erlang, C, Perl, LaTeX

Open Source Software

• EUnit, a unit testing framework for Erlang.
• EDoc, a Javadoc-like documentation system for Erlang.
• Syntax Tools, an abstraction layer for metaprogramming with Erlang syntax trees.
• Speccylator (1993-1997), a Z80/ZX Spectrum emulator for Amiga/MC680x0.

Talks

• The art of the live upgrade - 10 yrs of evolving a live system, Code BEAM SF 2019
• Secrets of the Erlang Beam compiler, Erlang & Elixir Factory SF 2017
• Erlang Metaprogramming Made Easy, Erlang Factory SF Bay Area 2012

Publications

• Erlang and OTP in Action
  • (Logan, Merritt, Carlsson)
• Erlang's Exception Handling Revisited
  • (Carlsson, Gustavsson, Nyblom) ACM Erlang Workshop '04, Snowbird, Utah, Sep. 2004.
• Message Analysis for Concurrent Programs Using Message Passing
  • (Carlsson, Sagonas, Wilhelmsson) ACM Transactions on Programming Languages and Systems, Volume 28, Issue 4, pp 715–746. (Extended version of the SAS'03 paper.)
• Message Analysis for Concurrent Languages
  • (Carlsson, Sagonas, Wilhelmsson) In: Cousot, R. (eds) Static Analysis. SAS 2003. Lecture Notes in Computer Science, vol 2694.
• Parameterized Modules in Erlang
  • (Carlsson) ACM Erlang Workshop '03, Uppsala, Sweden, Aug. 2003.
• Hierarchical Module Namespaces in Erlang
  • (Carlsson) ACM Erlang Workshop '02, Pittsburgh, USA, Oct. 2002.
• An Introduction to Core Erlang
  • (Carlsson) PLI'01 Erlang Workshop, Firenze, Italy, Sep. 2001.
• Core Erlang 1.0.3 Language Specification
  • (Carlsson et al.) Technical Report no. 2000-030 from the Department of Information Technology, Uppsala University, Nov. 2000.
• Extending Erlang with structured module packages
  • (Carlsson) Technical Report no. 2000-001 from the Department of Information Technology, Uppsala University, Jan. 2000.
• Towards a Deadlock Analysis for Erlang Programs
  • (Carlsson) Uppsala Master's Theses in Computing Science 108, Apr. 1997.

Education (by selection)

1998 – 2004 Postgraduate Student, Uppsala University

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