logo inner

Senior Software Engineer (Frontend) - Core

Five9Porto, PortugalHybrid

Join us in bringing joy to customer experience.  Five9 is a leading provider of cloud contact center software, bringing the power of cloud innovation to customers worldwide.   
Living our values everyday results in our team-first culture and enables us to innovate, grow, and thrive while enjoying the journey together. We celebrate diversity and foster an inclusive environment, empowering our employees to be their authentic selves. As a member of the Core Apps Team, you will be working on maintaining and enhancing Five9’s legacy applications. We are looking for an experienced engineer who is passionate about building stable, high-performance, and reliable solutions, possesses strong analytical thinking, and can effectively collaborate within a team.If you are looking to work with proven technologies, help maintain mission-critical systems, and grow in a stable environment, we'd love to have you on our team!

Key responsibilities: 


  • Support and enhance legacy applications, ensuring their stability and improving code quality.
  • Develop and maintain Java UI applications using WebSwing.
  • Work with JSF, JSP, and other web interface technologies.
  • Optimize and maintain existing code while reducing technical debt.
  • Conduct code reviews, write unit tests, and follow best development practices. 
  • Collaborate with cross-functional teams, including Product, QA, and Operations, to ensure successful implementation of new solutions.
  • Work with SQL and NoSQL databases, participating in query optimisation. 
  • Utilize CI/CD tools such as GitLab.

Requirements:


  • 5+ years of experience in software development.
  • Strong knowledge of Java and experience with WebSwing, Java UI.
  • Knowledge of Spring framework is a plus.
  • Experience with JSF, JSP is a plus. 
  • Solid understanding of SQL and NoSQL databases.
  • Knowledge of Kubernetes and cloud solutions (e.g., GCP) is a plus.
  • Experience working in a CI/CD environment.
  • Strong debugging and optimisation skills.
  • Ability to work effectively within a team, solve complex problems, and suggest improvements.
  • Willingness to be on-call when necessary. 

Benefits:


  • Five9 Shares
  • Bonus Scheme
  • 10% Flexi Benefit
  • Meal Allowance
  • Medical Insurance
  • Life Insurance 
  • 25 day Annual Leave + Public Holidays

Five9 embraces diversity and is committed to building a team that represents a variety of backgrounds, perspectives, and skills.  The more inclusive we are, the better we are.  Five9 is an equal opportunity employer.View our privacy policy, including our privacy notice to California residents here: https://www.five9.com/pt-pt/legal.  Note: Five9 will never request that an applicant send money as a prerequisite for commencing employment with Five9.

Life at Five9

Five9 is a leading provider of cloud contact center software for the digital enterprise, bringing the power of cloud innovation to customers and facilitating more than three billion customer interactions annually. Five9 provides end-to-end solutions with omnichannel routing, analytics, WFO, and AI to increase agent productivity and deliver tangible business results. The Five9 platform is reliable, secure, compliant, and scalable; designed to create exceptional personalized customer experiences. For more information visit www.five9.com.
Thrive Here & What We Value1. Teamfirst culture2. Inclusive environment3. Empowering employees' authenticity4. Celebrating diversity5. Living values daily for team-first culture, innovation, growth, and enjoyment6. Embracing diverse backgrounds, perspectives, skills7. Providing benefits (Five9 SharesBonus Scheme, 10% Flexi Benefit, Meal Allowance, Medical Insurance, Life Insurance, Annual Leave + Public Holidays)8. Celebrating diversity and fostering an inclusive environment9. Embracing change and accepting new responsibilities10. Active commitment to diversity, equity, and inclusion

Related Sub

This job belongs to these sub. Explore related roles here:
Frontend developer remote jobs
Your tracker settings

We use cookies and similar methods to recognize visitors and remember their preferences. We also use them to measure ad campaign effectiveness, target ads and analyze site traffic. To learn more about these methods, including how to disable them, view our Cookie Policy or Privacy Policy.

By tapping `Accept`, you consent to the use of these methods by us and third parties. You can always change your tracker preferences by visiting our Cookie Policy.

logo innerThatStartupJob
Discover the best startup and their job positions, all in one place.
Copyright © 2025