Scalable Next.js Commerce Upgrade

Empleador

Maxwell Kovach

Descripción

We are moving a production e-commerce site from a brittle monolith to a fully type-safe stack based on Next.js 14, NestJS, PostgreSQL, Auth.js, and Stripe.

The immediate priority is a thorough refactor of the existing legacy codebase to reduce high server response times affecting checkout and catalogue pages.

After the main bottlenecks are resolved, the roadmap includes clean REST/GraphQL APIs and a hardened Stripe integration, built with TDD and modern best practices.

The project is already in a GitHub repo with CI configured for Jest and ESLint. Every merge must keep tests passing and Lighthouse scores healthy.

Tech stack:

- Next.js 14 frontend

- NestJS services layer

- PostgreSQL 15

- Auth.js sessions

- Stripe payments

- Jest, ESLint, CI

Priority order:

1. Refactor legacy code

2. Build clean APIs

3. Finalise secure payments

Ideal freelancer:

Someone who has shipped similar e-commerce or SaaS projects, preferably using Next.js and NestJS. Experience with performance optimisation, API design, Stripe webhooks, testing, and production-grade refactoring is important.

Please include links to relevant demos, repositories, pull requests, benchmarks, or case studies if available.

Publicado

el 2026-05-22

Categoría

Crear tiendas en línea

Derechos de autor

Decisión del freelancer

¿Plantilla o diseño individual?:

This is not a template-based project. The work is focused on upgrading and refactoring an existing custom production e-commerce platform. The current frontend is built with Next.js 14. The goal is to preserve the existing business logic where appropriate, improve the architecture, and optimise performance. No new graphic design is required at this stage, unless small UI adjustments are needed to support checkout, catalogue performance, or API changes.

Funciones requeridas:

Required functionality and deliverables: 1. Legacy code refactor - Identify and remove major performance bottlenecks - Improve checkout and catalogue page response times - Keep existing functionality stable - Maintain type safety across the stack 2. Performance requirements - p95 API response time under 200 ms under 500 concurrent users - k6 performance test script will be provided - Lighthouse scores should remain healthy 3. API work - Build or update clean REST/GraphQL APIs - Document endpoints with OpenAPI - Verify endpoints using a Postman collection 4. Stripe integration - Complete Stripe checkout flow in test mode - Implement secure webhook handling - Add graceful failure paths for payment errors, cancelled payments, and webhook issues 5. Testing and CI - Existing unit tests must continue passing - Add new tests where needed - Jest and ESLint must stay green in CI 6. Handover - Record a pull-request walkthrough using Loom or similar - Explain architectural decisions so the in-house team can maintain the work