Software Engineer (Next.js / React)

This role is suitable for a Senior Software Engineer with strong hands-on expertise in Next.js and React, daily experience using AI coding tools such as Cursor or Claude Code, and fluent English communication skills. The candidate should be experienced in owning products end to end, making technical decisions, and communicating effectively with non-technical stakeholders. They should be familiar with shipping features, improving existing portals, managing codebases, collaborating directly with leadership, and working full time with U.S. Eastern/Central time overlap.

1. How would you structure a production-grade Next.js application for a portal that you own end to end?

I would define clear boundaries between UI, server-side business logic, data access, and integrations. I would use reusable React components, typed interfaces, environment-specific configuration, consistent error handling, and automated testing so the codebase remains maintainable as the product grows.

2. When would you use Server Components, Client Components, Server Actions, and API route handlers in Next.js?

I would prefer Server Components for data fetching and rendering that do not require browser interactivity. Client Components are appropriate for stateful or interactive UI, while Server Actions and route handlers can encapsulate secure mutations and API endpoints, depending on integration and caching requirements.

3. How would you improve the performance of a slow React and Next.js portal?

I would measure first using browser profiling, Web Vitals, and application monitoring. Then I would optimize data fetching, caching, bundle size, image handling, rendering boundaries, database queries, and unnecessary React re-renders, validating each change with measurable results.

4. How would you design authentication and authorization for a portal containing candidate, staffer, client, and company information?

I would implement secure authentication with protected server-side sessions and enforce authorization on the server for every sensitive operation. Role-based or permission-based access control, input validation, secure cookies, audit logging, least-privilege database access, and careful protection against IDOR vulnerabilities would be essential.

5. How would you safely implement a feature that requires changes to an existing production database?

I would create a backward-compatible migration, deploy schema changes before application changes when necessary, and handle old and new data formats during the transition. I would test the migration on realistic data, create backups or rollback procedures, and monitor the deployment closely.

6. What testing strategy would you use for a business-critical Next.js portal?

I would combine unit tests for business logic, component tests for important UI behavior, integration tests for APIs and database interactions, and end-to-end tests for critical workflows. Tests should run in CI, with particular focus on authentication, permissions, data mutations, and high-value user journeys.

7. How would you design reliable data fetching, caching, and revalidation in Next.js?

I would classify data by freshness and sensitivity, then choose appropriate caching and revalidation policies for each resource. Frequently changing or user-specific data would avoid unsafe shared caching, while stable data could use controlled revalidation, explicit invalidation, and loading and error states.

8. How do you use AI coding tools such as Cursor or Claude Code without compromising code quality or security?

I use AI tools to accelerate exploration, implementation, refactoring, and test generation, but I review every output and verify it against requirements and existing architecture. I do not expose secrets or confidential data, and I validate generated code through tests, security review, type checking, and manual inspection.

9. How would you release a major portal feature while minimizing risk to business operations?

I would break the work into small, observable changes and use feature flags or staged rollout when appropriate. Before release I would verify tests, migrations, monitoring, permissions, and rollback steps, then communicate the release plan and follow up on production behavior.

10. How would you explain a significant technical decision to a non-technical CEO?

I would explain the available options in terms of business impact, cost, delivery time, reliability, security, and future flexibility rather than implementation details alone. I would state my recommendation, assumptions, risks, and trade-offs clearly, then document the decision and its expected outcome.

CAS is an accounting and finance talent firm seeking a Software Engineer to own its core business portal end to end. You’ll build and ship features, improve the existing product, and make technical decisions while working directly with the CEO and web developer using Next.js, React, and AI coding tools such as Cursor or Claude Code. This is a permanent, exclusive remote contractor role for professionals in Latin America, with U.S. Eastern/Central time overlap, paying $5,000–$7,000 USD per month with potential for more based on experience. Apply for meaningful product ownership, direct leadership access, and the opportunity to shape a business-critical platform in a long-term role.