[Remote] Senior Full Stack Engineer (BE focused0

Note: The job is a remote job and is open to candidates in USA. Avenue Code is a consultancy company seeking a Senior Full Stack Engineer with a focus on back-end development. This role involves designing and building scalable back-end APIs, managing database architectures, and contributing to full-stack integrations while mentoring junior engineers.ResponsibilitiesSystem Architecture & API Development — Designing, building, and scaling robust, efficient back-end APIs that power our front-end, with a strong sense of what makes an API clean, secure, and performantData & Storage — Owning database schemas, querying patterns, and storage strategies; understanding how data architecture decisions directly affect the product experience and system scalabilityFull-Stack Integration — Owning the full request lifecycle, from data persistence and messaging layers up to the API and UI interactionBack-End Performance & Security — Implementing caching strategies, optimizing database queries, managing asynchronous events/messaging, and ensuring robust authentication/authorizationFront-End Contribution — Writing clean, maintainable code within our React/Next.js ecosystem to consume APIs and deliver cohesive user experiencesTest Coverage — Writing comprehensive unit, integration, and functional tests (focusing heavily on API and database reliability) that keep the codebase stable as it scalesEngineering Culture — Leading code reviews, mentoring junior and mid-level engineers, and helping define the engineering standards we hold ourselves toSkillsBack-End Framework & Messaging: NestJS on Node.js / Express, REST + OpenAPI/Swagger (Scalar), Kafka, TypescriptData & Storage: MongoDB + Mongoose (migrations via ts-migrate-mongoose), AWS S3Auth & Integrations: NextAuth, JWT, Stripe, PersonaBuild / Infra / DevOps: Docker & docker-compose, GitHub Actions, AWSCore Front-End: React, Next.js (App Router), TypeScriptClient State & Data: TanStack React Query, Zustand, ImmerStyling: Tailwind CSS, Emotion, CSS Modules, PostCSSObservability: PostHog, WinstonI18n: next-intl, i18next / react-i18next, DittoTesting: API: Vitest, Supertest, mongodb-memory-serverWeb: Jest, React Testing Library, StorybookCode Quality: ESLint 9, Prettier, Husky, lint-staged, Knip, Code CoverageCompany OverviewAvenue Code is an IT consulting firm that specializes on Agile ecommerce software development. It was founded in 2008, and is headquartered in San Francisco, California, USA, with a workforce of 1001-5000 employees. Its website is http://www.avenuecode.com.Company H1B SponsorshipAvenue Code has a track record of offering H1B sponsorships, with 4 in 2026, 4 in 2025, 6 in 2024, 7 in 2023, 11 in 2022, 11 in 2021, 12 in 2020. Please note that this does not guarantee sponsorship for this specific role.