We are happi

We are a highly experienced team, that loves problem solving and coding. We are passionate about programming languages, Erlang in particular, and language design.

Our previous experience includes everything from building highly scalable and fault tolerant systems for the Swedish payment industry, assignments for health care projects and startups, to design and development of a cloud-based AI service to optimize material and energy consumption in laser cutting of sheet metal parts.

In short - we have the competence, experience and drive that meets the needs of both your demands and your wishes.

Erik Stenman


    “My vast experience and skills within both frontend and backend languages and architecture makes me a complete hacker.”

  • PhD in Computer Science from Uppsala University.
  • Former CTO of Klarna. Built the Engineering Department from scratch in 2005 to about 80 people in 2010.

Anna Attefall

Consultant Manager

    “I´m a pragmatic project manager that believes in the power of good people and a good team. Have experience of and knowledge from all parts of a project; requirement, developing and testing. I'm a former hacker, and still am at heart.”

  • Master of Science in Computer Science from Uppsala University.
  • Team leader, project manager and CEO of startup companies.
  • Wide experience from IT, Swedish and Nordic Health care and medical technology.

Tobias Lindahl


    “I´m an expert backend hacker within Erlang, compilers, virtual machines, optimization and runtime systems.”

  • Master of Science in Engineering Physics from Uppsala University.
  • Former member of Klarna's Technical Advisory Board and Architect group.

Jim Wilenius


    “My specialities are foremost within Java, algorithms, AI, machine learning, and architecture.”

  • PhD in Computer Science from Uppsala University.
  • Previously headed up the R&D team at Tomologic, responsible for designing and implementing Tomologic's core optimization service.

Richard Carlsson


    “I have deep skills within compilers, virtual machines, domain specific languages, runtime systems, and development tools.”

  • Master in Computer Science from Uppsala University.
  • Member of Klarna’s core team for many years.
  • Has contributed to many parts of the Erlang standard libraries, compiler, runtime system, and the Erlang language itself.

Let’s talk and work together!

Happi Hacking AB
Munkbrogatan 2, 5 tr
111 27 Stockholm