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Five9

Five9

San Ramon, California, United States of America

1K-5K Employees

Tech

Senior Software Engineer - Frontend

Porto, Portugal

Posted on Sep 18, 2026

Full TimeSeniorHybridAI Automation & Architecture

Job Description

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. 

Five9 has led the cloud revolution in contact centers, helping organisations transition from legacy premise-based solutions to the cloud. The cloud contact center market has become the hot space for innovation in real-time communications, and is the tip of the spear for the application of Artificial Intelligence, especially Generative AI and Large Language Models (LLM). Our innovative AI team is responsible for developing a suite of leading edge AI products built upon industry-leading AI tech from vendors like OpenAI, Google, and Amazon. These products include enterprise voice and chatbots (think: ChatGPT for businesses), agent assistance, and conversation analytics. This team - the fastest growing at Five9 - is seeking a talented and experienced Senior Front End React/Redux Software Engineer. In this role, you will be part of the team that builds software that brings AI technologies to users. Prior AI experience is not required - you will receive on-the-job experience for some of the hottest skills on the market. An ideal candidate for us is an experienced engineer who is passionate about building high performance web platforms and applications, a brilliant problem solver and a creative self-starter.

 

Key Responsibilities:

  • Implement UX designs by working with UX Designers on a day-to-day basis, using React/Redux based framework.
  • Build custom widgets for dashboards developed using Google Looker Studio plugins.
  • Be part of an agile team to develop a scalable, highly available application platform using modern PaaS platforms such as GCP.
  • Participate and contribute to requirements analysis and grooming.
  • Understand how to leverage PaaS components, such as CDN, noSQL databases when developing software in order to achieve scalability, reliability, and operability.
  • Document and communicate clearly architecture and implementation solutions.
  • Have ownership of your code in production, including on-call, troubleshooting.

 

Key Skills:

  • 5+ years software development experience.
  • React/Redux focus.
  • Highly proficient in JavaScript and TypeScript.
  • Experience in operational code ownership – on-call, troubleshooting, uptime
  • Experience in applying modern UI design patterns and separating concerns in a distributed system.
  • Must have experience working within an Agile/Scrum team.
  • Positive, self-motivated and enthusiastic attitude with a strong sense of ownership.
  • Strong pro-active communication skills, both verbal and written.
  • Experience in contact center software is a plus but not required.
  • Experience with custom widget development using Google Looker Studio is a plus but not required.

Workplace location: This role is fully remote for candidates who reside outside Porto, Maia, Matosinhos, Gondomar, Valongo e Vila Nova de Gaia.  Candidates who reside within those municipalities would be required to work in-office 3 days a week. 


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.

About Five9

Five9, Inc., together with its subsidiaries, provides cloud software for contact centers in the United States and internationally. The company offers virtual contact center cloud platform that delivers a suite of applications, which enables the breadth of contact center-related customer service, sales, and marketing functions.

Its solution enables its clients to manage these customer interactions across various channels, including voice, video, chat, email, website, social media, click-to-call,...

Job overview

Employment type

Full Time

Experience level

Senior

Work type

Hybrid

Department

AI Automation & Architecture

Posted

on Sep 18, 2026

About

Job Link

www.five9.com

Financials

Type

public

Annual Revenue

$500M-$1B

Market Cap

$5B+

Membership

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