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Senior Software Engineer – Frontend
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- Remote from
- Portugal
- Salary
- Undisclosed
- Department
- Software Engineering
- Employment
- Full Time
- Experience
- Senior
- Published
- Apply before
- 11 Nov 2026
- Listing views
- 198
- Application actions
- 14
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The role, at a glance.
Five9 is hiring a Senior Frontend Software Engineer to build AI-enabled cloud contact-center applications. The role centers on implementing UX designs with React, Redux, JavaScript, and TypeScript, including custom Google Looker Studio dashboard widgets. The engineer will work in an Agile team on a scalable GCP-based platform and use cloud components such as CDNs and NoSQL databases. This position includes production ownership, on-call troubleshooting, architecture documentation, and close collaboration with UX designers. It is remote within Portugal, although candidates in specified Porto-area municipalities are expected to work in the office three days per week.
Role DNA
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Pace & Pressure
4/5Autonomy Level
4/5Communication Load
4/5Salary analysis
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Core skills
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Sample interview questions
I would organize the application by feature domain, keep reusable UI components separate from feature-specific containers, and establish clear boundaries for state ownership. I would use Redux for shared or cross-cutting state, while retaining local component state where global coordination is unnecessary. Typed actions, selectors, API abstractions, and consistent testing conventions help preserve clarity as the codebase expands.
I would first define update frequency, data volume, and user interaction needs, then avoid unnecessary renders through memoization, stable props, and selective state subscriptions. For large datasets, I would use pagination, aggregation, virtualization, or server-side filtering as appropriate. I would also monitor rendering and network performance, handle loading and error states, and ensure the widget remains accessible and responsive.
I begin by reviewing flows, responsive behavior, interaction states, accessibility requirements, and unclear edge cases with the designer. I break the design into reusable components, implement a consistent design-token approach where available, and validate the result against the intended user journey. I also include error, empty, loading, and keyboard-navigation states rather than implementing only the ideal visual path.
I ensure the application has actionable monitoring, meaningful client-side error reporting, dashboards, and documented runbooks before an incident occurs. During an incident, I prioritize user impact, quickly narrow the issue through logs and telemetry, communicate status clearly, and deploy a safe mitigation or rollback. Afterward, I document the root cause and drive preventive improvements such as tests, alerts, or resilience changes.
I would use a CDN to cache static frontend assets close to users, apply cache-control policies carefully, and version assets to enable safe releases. A NoSQL database can support high-throughput, flexible data access patterns when its schema and partitioning are designed around the application's query needs. I would work with backend and platform engineers to define reliability, security, observability, and cost requirements rather than treating these services as isolated implementation details.
About this role.
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.
Five9 is committed to providing reasonable accommodations for qualified individuals with disabilities throughout the application and interview process. If you need assistance or an accommodation due to a disability, please contact us at accommodations@five9.com to request an accommodation. Requests will be handled confidentially and in accordance with applicable law.
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.
Annual salary information is not provided for this position. Explore salary ranges for similar roles in our Salary Directory ›
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