Millions of people across the world are determined to overcome big personal challenges such as alcoholism, depression and anxiety. But often tech makes this harder, leaving people feeling only more isolated.
We believe that support from real human beings is at the heart of getting better. Circles was founded in 2016 to harness tech to bring people truly closer, and turn their will to help each other into a real way to help.
Our app encourages a small group of committed people to stay closely in touch with someone who needs their help, using our “prompting engine” and data science tools. You’ll be a leader in developing this unique tech, building the back-end systems, and helping guide the development of the front-end. We’ve got a fantastic base of real users already giving vital feedback, ahead of our wider launch in 2017.
You’ll be a senior member of our small team. Working directly with leads and our founders, you’ll be programming, leading technical coaching and code review and sharing best practice with our growing team. You’ll also need to love working fast.

Engineering is a core function at Circles. Our engineers work side by side with the product team, and our engineering is a servant of making the best product we can. We have some deep problems to solve:

  • We want to provide users with helpful insights about their behaviour without compromising their privacy. How can we do complex data analytics and machine learning in the constraints of smartphone platforms? How can we train these techniques when we don’t have direct access to the original data?
  • Our users expect Circles to be there when they need it. How can we maintain a backend that we release almost continuously, yet is always available?
  • Our end users are not technical. How can we keep their app up to date and easy to use without introducing end user complexity? How do we “fail safe”, leaving them with as much functionality as we can?
  • We want to use the shared experiences of our users to give help to more people, but never let the experiences of an individual leak out. Can we implement differential privacy techniques successfully, even on our trial datasets? Can we scale them as we grow?
  • How can we use our expertise to help cutting edge medical research via our academic partnerships?

Every engineer will help us achieve all of the above, and more. In addition to these wider goals, you will:

  • Contribute to the design and development of our front-end platforms, in both native and cross platform code.
  • Work closely and constructively with our back-end team
  • Attract the best talent by always choosing the best new tech for the problems we’re solving
  • Respect the vulnerabilities of our users by building code that is secure and reliable
  • Champion good testing practice and keep hold of the team’s excellence as we grow
  • Help us grow the team with your knowledge of how to make great hires and helping others learn


We’re not dogmatic about our technical choices, and try to use the best tools we can for the constraints of the problem we’re trying to solve. At the moment, we have:

  • A RESTful API backend, supporting front-end clients written in Swift (iOS), Java (Android) and ES6 (React Native and web).
  • A backend is based on Rails 5 hosted on AWS, storing data in S3 and PostgreSQL. As we grow the backend we’re expecting to add at least Go, Elixir and Cloudfoundry
  • Tech Ops; Terraform, LogEntries, Elastic Beanstalk and good old fashioned shell scripting; anything we can describe with code, is!
    Data analytics research in Swift and Ruby, moving out to Python, R and probabilistic languages as we need them.


  • Have a strong influence – you’ll be one of our first hires, and we’re not looking for people to just close JIRA tickets. We want your personality and vision to change our technology, culture and direction
  • Positive human impact – know that your work has the potential to significantly help thousands of people
  • Truly user-centered tech – you’ll be creating unique tech to solve sensitive and complex human problems. Rapid testing with real users is a vital part of how we want to work. We’re not trying to sell gadgets or games. You’ll be able to show that your tech really serves the user
  • Move fast but rarely break things – you’ll be joining a startup, with startup challenges and startup pace, but we’re also an experienced team, well supported and funded. You’ll enjoy all the small company benefits, without many of the small company worries.


  • Reward – competitive market salary and equity options
  • Kit – choose your equipment
  • Team – regular events
  • Your wellbeing – time and space for meditation, gym, nutrition and a subscription to the health app of your choice
    If you care passionately about using tech for human good, and thrive on doing things that haven’t been done before, we’d love to meet you.

Please apply before 20th February 2017