Clojure & ClojureScript consultancy

Gaiwan seeks to improve upon common IT industry practices, by making deliberate technological choices and focusing on simplicity. They use Clojure, a language known for its high developer productivity. Gaiwan develops several popular Clojure libraries, benefiting their clients, their own projects, and the wider Clojure community, and making the language itself more attractive. By strengthening Clojure and its ecosystem, Gaiwan contributes to enhancing the IT industry as a whole.

We worked with Gaiwan on a complex ClojureScript test runner, and an integration of our product with a popular service. In both instances, they managed their time and resources well, effectively navigated unknowns, delivered high-quality code and communicated clearly. We had nothing but positive feedback, and would highly recommend Gaiwan as a partner.

The Gaiwan team helped us deliver a flawless attendee experience for our conferences. They have created a Bespoke editing and rendering tool to meet ITRev's needs. Created a live streaming conference platform and integrated it into several services and much more. It has been a delight working with them.

We have worked with the Gaiwan team for a large part of our journey. This has included tooling improvements, architectural feedback, improvements to our testing approaches, and one-on-one coaching sessions with our developers.

Gaiwan was comissioned to create the Datomic database driver for Metabase, and worked with Eleven to integrate Metabase into our system. They completely took the pain away from us and let us focus on our core product.

How we give back

Through Gaiwan's educational arm, Lambda Island, all Gaiwan engineers create and maintain several popular Clojure libraries and tools. Check out the quality of our code in these open source projects.


Full featured next gen Clojure test runner.


Royally reified regular expressions.


A ClojureScript logging library based on goog.log.


Convert ANSI escape codes to Hiccup.


We also maintain community infrastructure, like the ClojureVerse forum and the clojurians-log Slack archive.

Our projects

Lambda Island Open Source

All Gaiwan engineers are active open source contributors, and we have several open source libraries we created and maintain, available through the Lambda Island brand.

These projects often stem from needs we saw in client projects, or in the community in general. By opening them up we make sure we can use these building blocks on subsequent projects.


Heart of Clojure

Gaiwan GmbH is the initiator and legal entity backing the Heart of Clojure community conference. We provide the organizational infrastructure to be able to pull off such an event, and manage a big chunk of the work that goes into organizing. We also provide a “parachute sponsorship”, patching up any holes in the budget that may arise.

Meet the Gaiwan team

  • Arne Brasseur (Berlin)

    Arne has been delivering software solutions for well over a decade, as well as coaching individuals and teams on topics both technical and organizational.

    Since 2013 he's been coaching and consulting companies solve complicated real world problems. He has a natural instinct to break down highly complex problems and explain them as a series of simple solutions.

    He loves a nice cup of tea, and likes to to go for runs.

  • Joshua Ballanco (Miami)

    Josh has built operating systems with Apple, local news sites with AOL, and served as the Chief Scientist for a world-wide distributed team of programming and design consultants.

    He even managed to complete his Ph.D. in Computational Evolutionary Dynamics along the way.

    He currently works remotely from his home in Miami where he lives with his beautiful wife and two young kids.

  • Bettina Shzu-Juraschek (Berlin)

    As a product manager / owner, Bettina has helped users relocate, learn languages, and get shopping deals online and in mobile apps.

    People have told her that her deep user insight and pragmatic approach to technical solutions are her superpowers.

    To balance all the screen time, Bettina practices yoga and meditate.

  • Laurence Chen (Taipei)

    Laurence is an experienced developer with a knack for understanding the needs of the customer, and delivering pragmatic solutions. He has created bespoke systems for Taiwan-based SMBs, and offers consulting to the LINE corporation.

  • Ariel Alexi (Rosh HaAyin)

    Ariel is a master's student with an insatiable thirst for knowledge. She's always eager to explore new programming languages like Python, C++, Java, and Clojure (which we introduced her to and she fell in love with), having built numerous projects with them.

    Oh, and one more thing: if you challenge her to a game of Mario Kart, be prepared for a fierce competition!.

  • Mitesh Shah (Mumbai)

    Mitesh learnt coding because of his desire to hack video games. This slowly turned to a passion for all things computer.

    Active contributor to OSS, he was also funded by ClojuristsTogether to work on Clojurians Log V2.

    He creates Clojure related screencasts on his YouTube Channel.

Get a free 20 minute consultation!

Let's grab a cup of e-tea and figure out how to relieve you of your business stress!