Software Engineer - Backend (Node.js/AWS)

About Keystone AI Keystone AI’s mission is to deliver the credential security every business and employee needs to thrive. Millions of consumers, and over 25,000 brands worldwide, such as Michelin, Air France, and Forrester, trust Keystone AI for industry-leading innovations, patented zero-knowledge security, and an unmatched user experience. Founded in Paris, Keystone AI has since established offices in New York and Lisbon, and has grown to more than 300 Keystone AIrs globally. We're looking for people who actively use AI tools to drive efficiency, creativity, and impact in their work. At Keystone AI, we drive innovation and value learning, strive for excellence in everything we do, and thrive as one team. Learn more about life at Keystone AI , including how we work , how we hire , and the benefits of being a Keystone AIr . About the role You will join one of the talented product development teams to work on feature development, with a primary focus on the company's business growth, on projects such as the evolution of the company's plans and pricing strategy, the trial experience, the payment experience, or the onboarding experience of our customers. As a team member within the organization, you will collaborate closely with the product manager, product designer, engineering manager, and front-end engineers within the team. You will play a pivoting role in innovating the ways the team could deliver value to impact the company's trajectory, both in the short-term and long-term. Location-Specific Information: You will be based in Lisbon, with English as your working language. At Keystone AI, we embrace a hybrid culture that combines the best of both worlds: the creativity and energy of in-person collaboration with the flexibility of remote work. Our model is designed to strengthen team connections while supporting individual productivity and work-life balance. To maximize collaboration, we come together in the office on Mondays, Tuesdays, and Thursdays, while Wednesdays and Fridays offer more flexibility for focused work. About our stack: Programming language: Backend (85% of codebase): NodeJS, Typescript Frontend / internal tooling (15% of codebase): React, Typescript Infrastructure and storage layer: AWS EC2, Amazon ECS, MySQL on RDS, Redis, S3 CI/CD: Sonarqube, Gitlab, Terraform, Ansible Logging and monitoring: ELK (Elasticsearch, Logstash, Kibana) Documentation and tooling: Confluence, Jira, Zoom, Slack At Keystone AI you will: Innovate! As an engineering member, you'll work closely with the teams to discover creative solutions that drive the company's expansion. Your efforts will not only enhance the trial and payment experience for our customers but also enable us to significantly increase and broaden the reach of our application. Pair with other engineers, work with product managers, project managers, and also our quality engineering teams in a highly collaborative environment where everyone shares ownership of the company's success Learn every day, and share your knowledge with your co-workers. Participate in and propose cross-team initiatives for improving the happiness and efficiency of your fellow Keystone AIrs. Requirements: 4+ years of experience in software development 3+ years of experience in developing backend applications, used by a reasonable amount of users 2+ years of experience working in a product-focused company Ability to work collaboratively in a team Willingness to learn and assist in the design and implementation of backend solutions Fluent in English We're Also Looking For: Have prior knowledge on payments, user management system or business growth Willing to develop a T-shaped skillset Have prior knowledge of AWS Know how to code, but also to deploy, test, and monitor cloud applications Enjoy writing clean code that is easy to maintain and understand Ability to actively use AI tools to drive efficiency, creativity and impact in the engineering scope What Keystone AI offers you: Flex Benefits - allocate a monthly amount to a pool of benefits Health insurance covered by Keystone AI 5 extra vacation days each year, plus your birthday off Company wide well-being days (one per quarter) Equal Parental leave - up to 20 weeks fully paid leave, within the first year of birth or adoption Work schedule exemption - plan your work schedule in alignment with your manager Donation matching program - Keystone AI will match your donations to organizations driving positive impact in historically marginalized communities Access mental health services through Spring Health, available for you and your family members Team building & social events - weekly lunch in the office and monthly happy hour and much more Diversity, Equity, Inclusion and Belonging at Keystone AI: As a truly international company—founded in France and distributed across France, US and Portugal—Keystone AI thrives off diverse perspectives. We value all aspects of diversity: gender identity, sexual orientation, ability, ethnic origin, social background, age, lifestyle, and more. We are committed to hiring a diverse community and fostering a culture where everyone is heard and belongs. See more about this here . Your interview experience: To know what to expect once you’ve sent your application, read about how we interview and hire at Keystone AI . Feel free to browse our blog to find more information about our product and how we work.