Senior Full Stack Developer

We are looking for our clients Data Science team for a Senior Full Stack Developer with strong frontend development experience and Python expertise. The client develops AI-driven and data-intensive applications and is looking for a consultant who can help build production-ready web applications and user interfaces for several ongoing projects. The consultant will work closely with data scientists and business stakeholders, helping transform ideas, PoCs, and MVPs into scalable solutions. The assignment includes work across multiple projects running in parallel, including AI-powered applications, intelligent document processing, mobile applications, and chatbot solutions. Key Responsibilities: Design and develop modern web applications Build intuitive and user-friendly interfaces for data science and AI solutions Develop backend services and APIs using Python Collaborate closely with data scientists, designers, and business stakeholders Drive frontend design decisions and help establish best practices Support productization of existing prototypes and MVPs Contribute to application performance, quality, and maintainability Required Skills: Several years of experience in full stack software development Strong frontend development experience with modern web technologies Strong hands-on experience with Python Experience developing both frontend and backend solutions Ability to work independently and take ownership of technical solutions Experience designing and building web applications from scratch Professional English communication skills Nice to Have: Experience working with AI, Machine Learning, Data Science, or LLM-based solutions Experience with FastAPI or Flask Experience with PostgreSQL and Docker Experience with Azure DevOps and CI/CD pipelines Experience with responsive or mobile-first application development Additional Information: The client is also open to considering separate frontend and backend specialists if a suitable full stack profile is not available. The team consists of data science professionals and is especially looking for someone who can complement their software engineering capabilities. Multiple projects are running simultaneously with ambitious timelines, requiring a proactive and hands-on approach. The work is performed on a time and materials basis. Location: Data science team is mostly located in Helsinki office. While it is not mandatory to work at their premises, they expect that the developer joins sprint and PI planning on site. Answer these questions separately in a few sentences and attach them to your application! (Mandatory!) - Do you have at least 5 years of professional experience in software development?* - Do you have strong experience building modern web frontends?* - Do you have professional experience with Python development?* - Have you designed or built web applications from scratch?* - Have you worked with AI, Data Science, Machine Learning, or LLM-based applications?* Please apply with your CV in English, clearly showing how you match the requirements and answer to the questions above. The client is continously reviewing candidates and we ask you to submit your application as soon as possible Allocation: 80-100%, depending on workload and project phase. Start date: August 2026 End date: 31.12.2026, possible extension Language: Fluent in English, Finnish is considered as a plus We offer you: We offer a versatile assignment where every day is different and interesting. We also offer a very competitive salary and good employee benefits. Are you interested in becoming a part of our dynamic team? The position will be filled as soon as a suitable person is found, so please be quick and submit your application! Please include your salary expectation in your application. For more information, contact Kimmo Kärsämä, tel. 050 412 7500, kimmo.karsama@lokki.fi <mailto:kimmo.karsama@lokki.fi> Explore Lokki, through our blog and website: https://www.lokki.fi/ <https://www.lokki.fi/> . Lokki Henkilöstöpalvelut Oy (Finnish for Seagull Recruitment Services) has been active in providing recruitment services since 2005 and we belong to The Private Employment Agencies Association HPL. Our vision is to provide the best customer experience with our reliable, humane and effortless service around Finland. Our most important asset is a person who, as we know, thrives in a reliable and supportive atmosphere. At Loki you will be supported by your own human resources consultant throughout your employment relationship. At Lokki, we believe in a partnership achieved as a result of flexible service. Explore us and our vacancies: https://www.lokki.fi/. You can also find us on Facebook and Instagram.