We are looking for a talented Junior Frontend Engineer to join our Frontend engineer team and help us change the world of digital advertising together.


Seedtag is the leading Contextual Advertising Platform. Our proprietary, machine learning-based technology provides human-like understanding of the content in the web, the highest level of brand safety in the industry and unmatched cookieless targeting capabilities.

We engage with the market on both demand and supply side to create, activate and launch high-quality advertising campaigns at scale. We are committed to creating a more beautiful, respectful and engaging way to do advertising.


2014 · Founded by two ex-Googlers

2018 · 16M total turnover & Internationalization & Getting growth

2021 · Fundraising round of 40M€ & +10 countries & +230 Seedtaggers


  • You will collaborate with the engineers programming and developing our company's web applications with React.
  • You will build new features for our employees and clients.
  • You will develop and deploy important tools to improve productivity of the whole company.
  • You will identify with the user and have a passion for appealing and intuitive interfaces.


  • You have knowledge of modern JavaScript/ES6.
  • You have experience with React and its ecosystem.
  • You have a strong understanding of HTML, CSS.
  • You have experience with GIT.
  • You have the ability to work in a disciplined environment.
  • You are a proactive person who likes the work culture of startups.



  • You will get to know the structure of the team and your colleagues.
  • You will get to know the tech stack of our web applications and all the communication tools we use.
  • You will start by understanding the structure of our web applications and the mission and vision of Seedtag.
  • You will be able to run the project and start building on it.


  • You will be an active part of the team by contributing to develop your first pieces of functionality of our administration tool.
  • You will improve your understanding of the Seedtag ecosystem.
  • You will be able to estimate tasks.
  • You will understand how to run web applications.
  • You will be able to create simple components and fetch data to populate them.

IN 6 MONTHS: Wow, you are in a good way!

  • At this point you will have the capacity to create and handle state between components helping to create a full feature.
  • You will have a better understanding of the server side of our applications.
  • You will be able to call our graphql apis server to fetch data using an api client (we use insomnia but you can use another api client if you feel better with another solution).
  • You will be able to suggest improvements and new features.


We are an AdTech family where innovative ideas and new ways to do things are welcome, we reject "that’s the way it’s always been done". In Seedtag you can find an energetic, fresh workplace, multicultural work environment where our members are from different countries from Europe, LATAM and so many more!, where you will have the chance to impact directly on the company results. Everyone is willing to help because we are all committed to a common objective, making Seedtag the best company in the world!

Seedtag DNA is unique from the very beginning, we celebrate and embrace diversity, also we want all our members (They, he or she) to feel like home, all of the human differences are welcome.


"Seedtag is an amazing place where to grow into a very good environment to try your best every day with interesting challenges working with great engineers but also with incredible people.” (Pablo Rodríguez, Frontend Teach Lead, Engineer’s Degree, father and always a big dreamer).


    • An unlimited remote working environment, where you can choose to work from home indefinitely or attend our Madrid headquarters whenever you want, where you will find great workplace location with food, snacks, great coffee and much more.
    • Flexible hours and work-life balance, we keep the focus on the results.
    • Personal development programs based on our career paths
    • Optional company-paid English and/or Spanish courses.
    • Access to learning opportunities (learning & development budget)
    • We love what we do, but we also love having fun. We have many team activities you can join and enjoy with your colleagues!
    • Access to a flexible benefits plan (plan de retribución flexible) with restaurant, transportation and kindergarten tickets and discounts on medical insurance.

    Want to be a Seedtagger? Then send us your CV, we are waiting for it!