11 - 25 employees
< 10 engineers
$10m - $25m funding
Series a

Three years after launching, someone, somewhere downloads Co-Star every 3 seconds. Every day, we generate millions of hyper-personalized horoscopes using rules-based natural language programming that combines state-of-the-art AI models like GPT-3 with the insights of staff poets. Understanding that astrology is about more than predicting the future, we approach it as part of $4.3tr wellness industry.

Active Roles 1 more active role

Why join us?

  • Every 3 seconds someone downloads Co-Star.

  • Over half of millennials and nearly a third of American adults believe in astrology.

  • Investors include people behind companies like Twitter, Vine, Warby Parker, Glossier, Discord, Away, etc. Last year we were worth $50m. Now we're worth $115m.

Engineering at Co-Star

Engineering team and processes

We’re big into cross-functional collaboration. Monthly, the entire company comes together to brainstorm new ways to hit our goals. We believe we can move the fastest when there is open communication between all members of the team (product designers, engineers, content, customer support, etc)

Weekly, we start the week with an iteration planning meeting to estimate and scope stories. We use GitLab to do code reviews.

Technical Challenges

• Scaling our backend infrastructure to millions of daily users • Space geometry - we calculate horoscopes based on angles between different planets/asteroids in the solar system. • Transforming structured data into unique, personalized horoscopes for each specific time/date of birth using a custom domain specific language for constructing formulas based on astrological inputs.

Projects you might work on
  • • Our primary focus of engineering is our mobile app. One example of a recent project was adding related friends to people's daily updates. This involved changes across the whole stack, including thinking about permissions, custom views, performance testing, and backwards compatibility.

  • • We develop internal tools to give our content editors super powers. Part of this includes a DSL which can be interacted with via a visual editor.

Tech stack
AWS Lambda

Working at Co-Star

We value intelligent, thoughtful, problem solving. We respect each other's opinions, experiences, and backgrounds and talk out challenges until we arrive at a solution. We're constantly collaborating, communicating, and moving forward.

Perks & benefits
  • Generous Vacation

    Unlimited vaca, 4 week minimum.

  • Free Food


  • Flexible Hours
  • Health Insurance
  • Workshops/Conferences
  • Work from Home
  • Beautiful Office
  • Women-led company
  • Minority-led company
  • Prioritizes diversity in hiring
  • LGBTQ+ friendly
  • Social impact driven
Our Team by the Numbers

Interested in this company?
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