Senior Backend Engineer

We are a tech company based in Palo Alto and Madrid on a mission to reinvent the e-commerce world using machine learning. We have several products focused on giving companies the ultimate tool to achieve the perfect flow to improve, measure and track all the information and transactions related with their company.

We are seeking a Senior Backend Engineer who wants to join our awesome team in Madrid. As a Senior Backend Engineer you will:

Collaborate with product and frontend teams to iterate on the implementation of the current product and build new features.

Help your backend team to improve their skills and learn from them. Lead code reviews and do pair programming with all the team.

Help to define architecture and make decisions about new specifications. Help the rest of the teams to participate in it.

Work with frontend team in definition, architecture and code implementation.

Participate in business and product decisions. As you gain context, you should provide guidance and input on your teammates’ approaches, based on your experience, knowledge and interests.

Suggest improvements in the company (culture, actions, etc.) or in the code. We love refactor and we do not believe in code "perfection" but clean code culture is something we value. Help your teammates to be better professionals.

Build maintainable services that can scale. You will not only develop libraries and abstractions to help platform performance and maintainability, but also be responsible for the testing coverage of the platform.

Be responsible for your code and help others to improve theirs, helping with testing, doing pair programming, etc.

Build a robust and easy-to-maintain backend structure.

Implement security and data protection features as well as notification mechanisms.

Required Experience

Experience with AWS ecosystem, including EC2, S3, RDS, DynamoDB, ELB, Kinesis, Elastic Search, etc. is required.

We work in a post‑agile culture so we are looking for responsible people who want to take over their work and make decisions about the implementation/way to proceed with some features or approaches.

Communication is a must with a multicultural team, living in different time zones so you have to be responsible for your own communication and raise your hand if something seems not working or can be improved. We also need a mid–high English level.

We are seeking proactive people who want to improve our culture, our values and help our company to reinvent the e-commerce world.

Helpful Skills/Experience

Docker knowledge is valuable.

Experience with technologies such as RabbitMQ or Kafka.

Notion of Machine Learning and Artificial Intelligence algorithms and frameworks such as Tensorflow.

Systems/Dev Ops knowledge and experience with micro‑services will also be valuable.

We have different products and some interest in Machine Learning/Data Science and experience integrating 3rd party payment providers, CRMs, CMS’ etc. will be valuable.

To apply for this role, please send your CV including a cover letter highlighting your unique qualifications to

Local candidates only – Principles only – No agencies please.