Senior Full Stack Engineer
ZeinCrew LLC – Remote | Full Time
About ZeinCrew
ZeinCrew is a staffing company that partners with some of the best and fastest-growing technology companies in New York City and globally. We connect exceptional professionals with innovative organizations, helping businesses scale their teams and achieve their growth objectives.
About the Role
We are looking for a Senior Full Stack Engineer to join a fast-paced engineering team building scalable, production-grade software products. This role involves developing end-to-end applications across the frontend, backend, APIs, databases, and cloud infrastructure, with opportunities to integrate and ship AI-powered features into real-world products. You will work closely with engineers, product managers, designers, and other cross-functional teams to turn product requirements into reliable, scalable solutions. We are looking for someone who is comfortable owning features from design and architecture through development, deployment, and ongoing improvement.
Key Responsibilities
●Design, build, and ship scalable full-stack applications across the frontend, backend, APIs, databases, and cloud infrastructure.
● Develop modern, responsive user interfaces using React, Next.js, and TypeScript, with an understanding of SSR, CSR, SSG, and performance optimization.
● Build robust backend services and APIs using Node.js, Python, or similar technologies, with a focus on performance, reliability, scalability, and maintainability.
● Design and integrate APIs using appropriate communication patterns such as REST, GraphQL, WebSockets, webhooks, and asynchronous messaging.
● Design and work with relational and NoSQL databases, caching systems, asynchronous workflows, and distributed services.
● Apply best practices for web performance, SEO, accessibility, and responsive application design. ● Integrate and ship AI/LLM-powered features such as intelligent automation, search, chat, or AI-assisted workflows into production applications.
● Collaborate with product managers, designers, and engineers to make technical and architectural decisions and take ownership of features from design through development, testing, deployment, and ongoing optimization.
● Contribute to code reviews, technical documentation, CI/CD, monitoring, production support, and engineering standards, while mentoring other engineers and helping improve system reliability and development practices.
Requirements
●5+ years of professional software engineering experience, with strong experience building and shipping production full-stack applications.
● Strong proficiency with TypeScript/JavaScript, React, and modern frontend development.
● Strong backend development experience with Node.js, Python, or similar technologies.
● Experience designing and building RESTful or GraphQL APIs and familiarity with other communication patterns such as WebSockets, webhooks, or asynchronous messaging.
● Understanding of modern web rendering approaches such as SSR, CSR, SSG, and ISR, and when to use them.
● Understanding of web performance, SEO, accessibility, and frontend optimization.
● Experience designing and working with relational databases such as PostgreSQL, as well as NoSQL databases where appropriate.
● Experience with AWS, GCP, or Azure, along with Docker and modern CI/CD practices.
● Hands-on experience integrating and shipping AI/LLM-powered features into production applications; candidates should be able to speak to an AI feature they have actually built, deployed, and maintained.
● Familiarity with technologies such as OpenAI, Anthropic, Gemini, or other LLM APIs.
● Strong understanding of software architecture, scalability, security, performance, testing, and clean coding practices.
● Strong communication skills and the ability to work independently in a fast-paced, remote environment.
● Demonstrated technical ownership and ability to take features from initial requirements through production.
Nice to Have
●Advanced experience with Next.js, including App Router, Server Components, Server Actions, middleware, caching, and rendering strategies.
● Experience with FastAPI, NestJS, GraphQL, WebSockets, SSE, or event-driven architectures.
● Experience with RAG, vector databases, embeddings, AI agents, tool/function calling, structured outputs, or multi-step AI workflows.
● Experience with Kubernetes, Terraform, Infrastructure as Code, Redis, Kafka, or distributed systems.
● Experience with AI observability, evaluation, tracing, or monitoring.
● Experience optimizing applications for SEO, Core Web Vitals, high traffic, and production-scale performance.
● Experience working at a startup, scale-up, or SaaS company with significant ownership over architecture and product decisions.
● Open-source contributions or experience mentoring engineers and providing technical leadership.
Why Work with ZeinCrew
●Remote role with flexible working environment
● Competitive compensation
● Collaborative and supportive team culture
● Opportunity to work with fast-growing startups
● Exposure to modern technologies and real-world products
● Opportunity to build and ship AI-enabled features without being limited to an AI-only role
● Long-term growth opportunities
