Engineering & Development - | - Senior - Senior - Europe - Colombia - Serbia - Montenegro - Slovakia - APAC - | - Europe - Colombia - Serbia - Montenegro - Slovakia - APAC - | - Remote - July 1, 2025 **About the company**: First Line Software works with some of the world's top businesses and organizations in industries like healthcare, data engineering, warehouse automation, retail digitalization, mobile app development, and e-commerce. Our projects are as varied as our people, and our people are as talented as they come. We prefer working as a transparent and supportive team, who shares our knowledge as well as our success. Let's see what we can create together.! **The project and your role**: **Responsibilities**: - Design, develop, and maintain robust, scalable back-end solutions using Optimizely CMS and Commerce platforms - Collaborate with front-end developers, architects, designers, and stakeholders to deliver seamless digital experiences - Develop integrations with third-party systems (APIs, payment gateways, CRM, etc.) - Ensure code quality through code reviews, unit testing, and best engineering practices - Participate in architectural discussions and technical decision-making processes - Provide technical mentorship to junior developers and actively contribute to knowledge sharing - Stay up-to-date with the latest Optimizely features, tools, and industry trends **Your skills**: **Requirements**: - 5+ years of professional back-end development experience - Solid expertise in Optimizely CMS and Commerce (minimum 2 years hands-on) - Strong knowledge of.NET Core, C#, and modern development frameworks - Experience with RESTful API design and integration - Solid understanding of software design principles, architecture patterns, and performance optimization - Familiarity with relational databases (e.g., SQL Server) and ORM tools - Hands-on experience with version control (Git), CI/CD pipelines, and Agile methodologies - Excellent problem-solving skills and attention to detail **Must have**: - Optimizely CMS and Commerce - NET Core - C# - Experience with headless CMS implementations **Nice to have**: - Optimizely Certification(s) - Knowledge of cloud platforms (Azure or AWS) - Familiarity with testing frameworks and automated testing practices **What we can offer**: **The FLS difference** - Our modern stack projects are the right mix of exciting and challenging - Gain access to our diverse range of training programs, courses, and certifications - Choose your work style - remote, on-site or hybrid in one of our stunning offices. We offer the freedom of flexible working hours - Enhance your language skills with our corporate English classes - Work from anywhere and explore the world with our Workation program **Language Proficiency**: - English - Our Hiring Process **Getting started with us**: **Step 0**: **Tech Talent Hunt**: - **Step 1**: **Meeting & Connecting**: - Our first step to building lasting relationships **Step 2**: **Uncovering Potential**: - Your HR interview **Step 3**: **The Code Challenge or Technical Interview**: - It's time to show what you can do best! **Step 4**: **Client’s Interview**: - Demonstrating expertise to our future partners **Final**: **The Last Piece of the Puzzle**: - Job offer to finalize our tech team **Join our team of innovative thinkers**: **Let’s talk!**: - Have any questions? Fill out the form and our team will be in touch!