Senior Software Engineer, Frontend

This role is suitable for a Senior frontend-focused software engineer with 7+ years of experience, based in the U.S. Eastern Time Zone and fluent in English. Required skills include expert React and TypeScript, production-scale UI development, UX, accessibility, performance optimization, AI-assisted development tools, technical leadership, mentoring, and working proficiency in Go. The candidate should be experienced in owning features end to end, setting frontend standards, making architectural decisions, collaborating with stakeholders, contributing to roadmaps, writing technical documentation, and working effectively in ambiguous, customer-focused environments.

How would you structure a large React and TypeScript application to keep it maintainable as the product and team scale?

I would organize the application by domain or feature, enforce clear boundaries between presentation, state, and data-access layers, and use shared design-system components for consistency. Strict TypeScript settings, documented conventions, automated tests, and code ownership would help maintain quality as the codebase grows.

How would you optimize the performance of a data-intensive fraud or risk dashboard?

I would measure first using browser profiling and real-user metrics, then address unnecessary renders, expensive computations, bundle size, and network latency. Techniques such as virtualization, pagination or streaming, memoization where appropriate, code splitting, caching, and server-side aggregation can improve responsiveness without sacrificing usability.

How do you design accessible React interfaces for users working with complex workflows?

I would use semantic HTML, keyboard-accessible interactions, visible focus states, appropriate labels, and correct ARIA only where native semantics are insufficient. I would validate the experience with automated checks and manual testing using keyboard navigation and screen readers.

How would you manage server state and asynchronous workflows in a TypeScript frontend?

I would separate server state from local UI state and use a consistent data-fetching approach with caching, request deduplication, retries, loading states, and error handling. Type-safe API contracts and explicit handling of stale or optimistic data are especially important for risk and compliance workflows.

How would you secure a frontend that displays sensitive financial and fraud-related data?

I would treat the frontend as an untrusted client, enforce authorization on the backend, minimize sensitive data exposure, and avoid storing secrets or unnecessary personal information in the browser. I would also apply secure session handling, input validation, safe rendering, auditability, and protection against common threats such as XSS and CSRF.

What is your approach to testing production-grade React and TypeScript features?

I would combine unit tests for business logic, component and integration tests for user workflows, and a smaller set of end-to-end tests for critical paths. Tests should cover accessibility, loading and failure states, permissions, edge cases, and realistic API behavior rather than only implementation details.

How would you build a Go API to support a frontend feature?

I would define the API contract first, including validation, pagination, error semantics, authorization, and observability requirements. In Go, I would keep handlers thin, isolate business logic, use context-aware I/O, validate inputs, and add unit and integration tests before integrating the endpoint with the React client.

How would you use AI tools such as Claude in software development without reducing code quality?

I would use AI for exploration, scaffolding, test generation, refactoring, and documentation, while keeping architectural decisions and final validation under human review. Generated code must pass type checks, tests, security review, linting, and careful inspection for incorrect assumptions, data leakage, or subtle business-rule errors.

How would you handle evolving requirements when building an ambiguous user-facing product?

I would clarify the user problem and success criteria, identify constraints and risks, and propose a thin vertical slice that validates the core workflow quickly. I would document assumptions, prioritize based on customer and business impact, and use feedback and measurable outcomes to guide subsequent iterations.

How do you establish frontend technical standards and mentor engineers on a distributed team?

I would establish practical standards through an evolving design system, architecture guidelines, review checklists, examples, and automated tooling rather than relying only on documentation. Mentoring would combine thoughtful code reviews, design discussions, pairing, and delegation that gives engineers ownership while maintaining a high quality bar.

Sardine is a leading agentic risk platform helping companies fight financial crime, prevent fraud, and automate risk operations. As a Senior Software Engineer, Frontend, you’ll build polished, accessible, high-performance experiences with React and TypeScript, contribute to Go-powered backend services, mentor engineers, and shape frontend standards using AI-assisted development tools. This is a full-time, remote-first role for candidates in the U.S. Eastern Time Zone, offering $145K–$195K plus equity. Apply to join a fast-growing, mission-driven team with flexible benefits, generous stipends, and the opportunity to define the future of AI-powered fintech security.