Python Backend Developer

Salary Competitive

CO2HERO is fast becoming the world's leading app to take climate action.

We connect businesses committed to a positive impact for the planet with a global community committed to making eco-friendly choices. In particular, we guide our users to cut down on their CO2 emissions through different lifestyle activities such as commuting, recycling, reusing, food …. just to name a few.

CO2HERO is a (SaaS) scale-up. Our clients are Fortune 500 companies. We have a global vision and exist to encourage change in everyday behaviour, in a balanced way.

As one of our customers said “CO2HERO is a one-stop platform for carbon-friendly actions that combines gameplay, competition, and climate science no matter where people may be in the world”.

With roots in Scandinavia, we continue to build momentum towards a better tomorrow - for all of us.

Based in Copenhagen, you will report directly to, and work closely with our Chief Technology Officer to bring to life our CO2HERO Development Strategy.

Join a development team with 8 different nationalities working out of our office in Copenhagen. Our company language is English, and we are working closely together across borders to improve our daily lives.


  • Backend development in Python, GraphQL/REST API’s and PostgreSQL

  • Interaction with other members of the project team

  • Estimation management, code review

  • Extending our proprietary framework (We are not using Django)

  • Analyzing and troubleshoot complex problems in a timely and accurate manner

  • Actively looking for security vulnerabilities in the code, in code reviews and in the project design

Required skills

  • 3+ experience with Python and SQL using psycopg2

  • Experience with advanced queries in SQL without using ORM

  • Experience with PostgreSQL

  • Experience with Panda & Numpy

  • Solid knowledge of object oriented programming and preferable with experience from a low level programming language

  • Experience with implementing based on security by design

  • Experience with performance tuning and improvements

  • Experience with caching

  • Write clean and well documented code

  • Analytical thinking

  • Experience with UnitTesting based on testing logic and not just code coverage


  • Understanding and experience with GraphQL

  • Experience with NoSQL databases

  • Experience with Git / GitHub

  • Experience with Microservice architecture and messaging

  • Experience working with AWS / Azure


You will be offered plenty of challenges every day working amongst a highly skilled, dynamic and ambitious team, all of whom have worked and lived across Europe, and North America. As CO2HERO is in rapid growth, you have the possibility to grow both in professional and personal aspects. Our offices are located in the heart of Copenhagen, Frederiksberg.


If you have an entrepreneurial spirit, get excited about finding smarter ways to do things, and have a burning desire to be part of a winning team where you can truly make a difference, we want to meet you.

Perks and benefits

This job comes with several perks and benefits

Flexible working hours
Flexible working hours

Time is precious. Make it count. Morning person or night owl, this job is for you.

Free coffee / tea
Free coffee / tea

Get your caffeine fix to get you started and keep you going.

Near public transit
Near public transit

Easy access and treehugger friendly workplace.

Social gatherings
Social gatherings

Social gatherings and games; hang out with your colleagues.

Remote work allowed
Remote work allowed

You know how you perform best. Work from your couch, your favorite cafe or abroad when you feel like it.

Work life balance
Work life balance

Carve out time for your kids, friends and personal cider projects.

See all 8 benefits

Working at

Climate change is impacting human lives in a variety of ways. It threatens the essential ingredients of good health – clean air, safe drinking water, food supply, and protection from catastrophic weather conditions. Each of us is responsible for climate change through our way of life. In particular, Co2 emissions are affected by what we eat, how we transport ourselves, where we live, and the products we buy. Most of us are aware there are consequences of those lifestyle choices. However, the consequences of each of our individual lifestyle choices are not fully transparent or easy to measure. We know we should reduce air travel, but we do not know the exact consequence / Co2 footprint of a weekend trip to Barcelona, the impact of becoming vegetarian or flexitarian, or getting an electric car instead of an ICE car. We would like to better understand the impact of these choices and get inspired from like-minded individuals across the globe. CO2HERO is a movement to better our daily lives. CO2HERO aims to be the epicentre of knowledge, providing transparency and insight, related to our global Co2 footprint to help people live and engage in a balanced, low-carbon lifestyle.

Read more about CO2HERO

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