Trivelta builds the technology that powers a modern online sports betting & casino platform that operators use to launch and offer their own fully customized branded, legally compliant iGaming platforms and products that drive engagement, retention, and revenue. Through our proprietary sports-book and casino engine, we enable partners to offer real social interactions, predictive gameplay, and casino entertainment in one unified experience.

The Role

As a Senior Frontend Software Engineer, you’ll play a critical role in shaping the core product platform. This platform powers our sportsbook and casino experiences, ensuring a seamless, engaging, and high-performing user journey. You’ll translate product and design concepts into clean, production-ready code while building scalable systems that serve as the foundation for our growth. This role is ideal for someone eager to influence product direction, iterate quickly, and deliver experiences that reach thousands of users from day one.

Key Responsibilities

• Build and maintain user-facing features in React and TypeScript, optimizing for responsiveness, performance, and cross-device compatibility.
• Collaborate with designers and backend engineers to deliver polished interfaces and intuitive user flows that scale with our product.
• Establish and maintain a reusable component library and design system to accelerate development and ensure consistency across the platform.
• Lead technical discussions on frontend architecture, performance tuning, and best practices to support a rapidly evolving product.
• Contribute ideas that shape product direction and deliverables, balancing speed with quality in a fast-paced startup environment.

 Qualifications

• Strong proficiency with React, TypeScript, and modern frontend tooling.
• Experience designing and implementing complex product flows and interactive user interfaces.
• Demonstrated ability to think about scalability, maintainability, and performance in frontend architecture.
• Proven track record of ownership across the full feature lifecycle in dynamic, startup-like environments.

Requirements

• Based in Barcelona 
• Fluent in English
• Minimum 4 years of relevant experience
• Hybrid- 4 days onsite
• EU work authorization required — no visa sponsorship

Secure Every Identity, from AI to Human

Identity is the key to unlocking the potential of AI. Okta secures AI by building the trusted, neutral infrastructure that enables organizations to safely embrace this new era. This work requires a relentless drive to solve complex challenges with real-world stakes. We are looking for builders and owners who operate with speed and urgency and execute with excellence.

This is an opportunity to do career-defining work. We're all in on this mission. If you are too, let's talk.

The Emerging Products Design Team

Emerging Products is an org pillar inside Auth0. We figure out what's next. You'll be designing systems that help developers secure AI agents, manage granular permissions, and build on identity primitives that don't fully exist yet.

Engineers, PMs, and Designers work on the same problems at the same time. There is no design-then-build sequence. There's just build.

What you’ll be doing

When everyone on the team can generate UI, the designer's role shifts. You become the person responsible for taste, quality, experience, and customer voice. You hold the quality bar when speed is pushing everything toward "fine."

• Prototype at volume: Use AI tools and code to explore dozens of directions fast, then narrow based on what works and what solves the actual problem.

• Design in the codebase: Work within our React and Next.js environment to refine components and interactions where users will actually experience them.

• Simplify complexity: Turn authorization models, SDK patterns, and security flows into interfaces that feel clear without losing precision.

• Raise the craft: Help the broader design org see what this way of working looks like in practice. We're all figuring this out together.

What you’ll bring to the role

• You have craft: This matters most. Considered typography, intentional spacing, polished micro-interactions, details that show someone genuinely cared. We're looking for someone with a refined sense of design taste/aesthetics and a deep appreciation for the details that create a polished user experience.

• You build: 6+ years of design experience, but somewhere along the way you started prototyping in the browser, shipping side projects, or writing production code because you wanted the interaction exactly right.

• You have a real AI practice: Not experimentation, but an actual workflow. You have opinions about where AI tools help and where they fall short.

• You design for developers: Tools, APIs, CLIs, SDKs, and admin dashboards. You know "simple" means something different for this audience.

Note for when applying

In your application, please include a link to your portfolio with password (if protected). We prioritize a review of your design craft and any examples of your work in code.

#LI-AR

#LI-hybrid

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Are you passionate about building cutting-edge sports statistics software? Our dynamic Stats team is dedicated to pushing the boundaries of technology, creating innovative solutions, and fostering a culture of mentorship and continuous improvement. You’ll work with the latest tools and technologies, take ownership of the entire product lifecycle, and collaborate with a talented team of engineers. If you’re eager to make a meaningful impact and grow in a supportive, high-performing environment, we’d love to hear from you!

We are one of the largest sports betting operators across Europe and have recently started our expansion into Brazil, making 1000+ location networks work across multiple geographies. If you ever wanted to see how software can handle 90 million bets per month - why not join us?

We have offices based in Madrid but will be offering full flexibility with occasional meet-ups with your teams and leads in the office as well as collaboration with our offices in London, Zagreb and more!

What you’ll be doing:

• Owning the full product lifecycle, from the initial proposal and planning to implementation, release, and ongoing maintenance
• Building innovative solutions using modern technologies such as TypeScript, Vue, React, AWS, CircleCI, and GitHub Actions
• Mentoring teammates to help them achieve high-quality results while meeting deadlines
• Leading initiatives to enhance the development experience for engineers across the organization
• Creating and maintaining build processes and tools to streamline workflows and boost team efficiency
• Leveraging best-in-class tools like Notion, Jira Cloud, GitHub, Zoom, Lattice, and Slack to maximize productivity and collaboration

What we’re looking for:

• A minimum of 5 years of hands-on experience with JavaScript and a strong understanding of its ecosystem
• High proficiency in developing applications with TypeScript
• Practical experience with Vue or React (ReactRouter & NextJs)
• Knowledge of modular software architecture, including microservices and microfrontends
• A proven ability to mentor teammates, manage time and priorities effectively, and resolve dependencies
• Experience in writing comprehensive and reliable tests to ensure code quality
• A track record of developing and maintaining build tools and toolchains to improve developer experience (DX)
• Strong attention to detail and a commitment to delivering exceptional products
• Deep understanding of best practices, design patterns, and core principles in software development
• Expertise in performance optimization techniques and their practical application
• Strong collaboration skills, with a history of building productive relationships with users and stakeholders
• A team-first mindset, thriving in collaborative environments where success is shared