Sr Software Engineer (Frontend Focus, Brazil)

AI overview

Design and implement frontend systems using React and TypeScript while contributing to a full-stack setup, with a focus on performance and collaboration across teams.

Kard is transforming customer loyalty with our rewards-as-a-service API platform. We empower our partners, from neobanks to financial institutions and beyond, to offer tailored rewards that celebrate customers' daily transactions. Backed by $30M from industry-leading investors and seasoned experts, we are reshaping the future of customer engagement.

About the Role

Design, build, and refine the frontend systems that power Kard's transaction-linked rewards platform. You will craft interfaces that serve our partners and their customers—performant, accessible, and built to last. The role is centered on React and TypeScript in an AWS environment, with backend work in Go, contributing to a flexible, full-stack experience.

Working closely with product, design, data, and other engineering teams, you will shape the frontend architecture, establish standards, and champion quality. You'll collaborate to turn product vision into reality—not just executing designs, but helping shape them. At Kard, we value engineers who are business thinkers, pragmatic problem solvers, and strong communicators. Whether refining component systems, improving test coverage, mentoring teammates, or leading a feature from canvas to production, you will have a direct impact on our technology and customers.

This role leans frontend—roughly 70/30—but you'll contribute across the stack when the work calls for it.

Responsibilities

  • Design and implement frontend systems in React and TypeScript, with attention to performance, accessibility, and maintainability.
  • Own the front of the frontend: design tokens, CSS architecture, and the tooling that makes styling scalable and consistent.
  • Establish and evolve **testing practices** that catch real bugs without creating brittleness—favoring tests that support refactoring over tests that fight it.
  • Contribute to backend services in Go, building APIs and integrations that support frontend needs.
  • Collaborate with product, design, and engineering to shape features from early concept through delivery, building in narrow vertical slices that deliver value continuously.
  • Drive frontend architecture decisions, balancing trade-offs between developer experience, optionality, performance, and business impact.
  • Improve automation, CI/CD, and observability for frontend systems, enabling faster iteration and more reliable releases.
  • Mentor engineers and **establish standards**—proposing them quickly, building consensus, shipping them, and evolving them thoughtfully when circumstances change.

Desired Skills

  • Expert-level React and TypeScript, with well-informed, contextualized opinions on ecosystem choices—when to reach for external state management, which patterns scale, what to avoid.
  • Deep appreciation for the craft of frontend development: CSS (and tools for managing it), design systems, accessibility, and the details that make interfaces feel right.
  • Strong linting and testing philosophy and practice—experience with Vitest, Playwright or Cypress, and an understanding of what makes frontend tests reliable rather than flaky. Bonus if you have thoughtful opinions on Visual Regression Testing.
  • Comfort working within Docker, Terraform, and Kubernetes environments. You don't need to be a DevOps specialist, but you can be productive within established patterns.
  • Experience building REST APIs, with an understanding of how frontend and backend responsibilities should be divided.
  • Business-minded approach to engineering: you deliver in vertical slices, you understand why features matter, and you collaborate with product and design to shape outcomes—not just implement specs.
  • Strong communication and collaboration skills, with experience working on small teams and mentoring other engineers.
  • Proficiency with AI-assisted development tools like Claude Code—you see them as complementary to your expertise, guide them critically, and integrate them into your craft.

Bonus Points

  • Experience with Go, or genuine interest in learning it.
  • Background with GraphQL or Backend-for-Frontend patterns.
  • Experience with mobile, especially Webview.
  • Experience with Databricks, MongoDB, or PostgreSQL.
  • Background in fintech, adtech, or transaction-based systems.
  • Contributions to open-source projects or active participation in the frontend community.
  • Prior experience in high-growth startups or scaling frontend infrastructure.

Salary Ranges

Brazil: $80,000 - $120,000 USD

Why Join:

Kard recognizes the unique value each of us brings to our collective success. As part of our remote-first team, you'll have the autonomy to influence our trajectory, actively contributing to the growth of our business and the evolution of our company culture. By embodying our core values of Initiative, Openness, and Humility, you will not only witness but directly foster an inclusive and dynamic work environment, from the executive level down.

Our competitive benefit plan includes:
  • Flexible PTO, with a minimum requirement to take one day off a quarter, ten days a year, promoting mental well-being
  • Observance of 11 Federal Holidays, plus an additional day each for Black Friday and Christmas Eve (US employees only)
  • Health, Dental and Vision Insurance
  • 401k with employer match (US employees only)
  • Coworking space and WFH setup reimbursement
  • Company Offsites two times per year for planning, team-building, and networking
Kard is an equal opportunity employer and we actively encourage applicants of all genders, backgrounds, and experiences to apply. We believe that diverse perspectives enrich our workplace and drive our success.

Perks & Benefits Extracted with AI

  • Health Insurance: Health, Dental and Vision Insurance
  • Company offsites for team building: Company Offsites two times per year for planning, team-building, and networking
  • Paid Time Off: Flexible PTO, with a minimum requirement to take one day off a quarter, ten days a year, promoting mental well-being

Kard is transforming customer loyalty with our rewards-as-a-service API platform. We empower our partners, from neobanks to financial institutions and beyond, to offer tailored rewards that celebrate customers' daily transactions. Backed by $30M from industry-leading investors and seasoned experts, we are reshaping the future of customer engagement.  

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Salary
$80,000 – $120,000 per year
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