Junior Developer

Junior Developer join the team Start your journey in a learning‑driven environment, inside a fast‑paced and ever‑evolving world of tech and innovation. At Celfocus, you’ll work with diverse teams on real projects and see how ideas turn into real impact. Hybrid ways of working, international projects, and the space to explore different paths as you grow. Explore your way in. About the role We are looking for a Backend to join an innovative team focused on building scalable, data-driven solutions. In this role, you will contribute to the development of backend systems while gaining hands-on experience in integrating AI and Machine Learning into real-world products. You’ll collaborate closely with experienced engineers, and product teams, learning by doing in a fast-paced and innovation-driven environment. As a part of your job, you will: Develop and maintain scalable backend services and RESTful APIs to support web and mobile applications; Collaborate with Data, and Product teams to design and deliver impactful solutions; Support the integration of Machine Learning models into production systems; Work with data pipelines, including data collection, processing, and transformation; Write clean, maintainable, and testable code, following best practices; Contribute to prototyping and experimentation of new AI-driven features; Monitor and improve performance, scalability, and reliability of backend systems; Participate in code reviews, technical discussions, and innovation initiatives; Assist in integrating backend systems with cloud platforms and services. What are we looking for? Basic knowledge of at least one programming language: Java, Python, or C++; Understanding of Object-Oriented Programming (OOP) principles; Familiarity with REST APIs and backend development concepts; Basic knowledge of Machine Learning fundamentals, including: Supervised and unsupervised learning; Experience or academic exposure to: Relational databases (SQL),Version control (Git – GitHub/GitLab); Backend frameworks (e.g., Spring Boot or similar); Exposure to Python data/ML libraries such as: NumPy, pandas, scikit-learn. Nice to have: Interest or exposure to Generative AI (e.g., LLMs, RAG, LangChain); Understanding of ML model deployment and serving via APIs; Basic knowledge of data pipelines or data engineering concepts; Familiarity with cloud platforms (AWS, GCP, or Azure); Awareness of MLOps practices; Basic frontend knowledge (HTML, CSS, JavaScript); Understanding of microservices architecture and distributed systems. Personal traits Ability to adapt to different contexts, teams, and Clients; Teamwork skills but also a sense of autonomy; Motivation for international projects and ok if travel is included; Willingness to collaborate with other players; Strong communication skills. A place for everyone At Celfocus, we are committed to cultivate a diverse and inclusive workplace. As an equal-opportunity employer, we welcome applicants of all backgrounds, gender identities, and abilities. If you require any adjustments during the selection process, please inform our Talent Acquisition Team. Department BL Digital | Chapters | Backend Development Role Backend Developer Locations Lisbon Work Model Hybrid Lisbon About Celfocus Celfocus is pioneering the future of business through Next-Gen Intelligence - the convergence of data, AI, and human creativity to build more autonomous and adaptive organisations. Guided by our core belief - Making Data Actionable - we partner with leading companies to co-create intelligent solutions that turn data into insight, agility, and business value. Operating in over 25 countries, we bring together business experts, data scientists, and AI engineers to turn complexity into clarity and vision into measurable impact. Founded in 2000, Celfocus is part of Novabase, listed on Euronext Lisbon. To know more, visit www.celfocus.com