Senior Full Stack Developer

At Similarweb, we are revolutionizing the way businesses interact with the digital world by revealing to them everything that happens online. Our unique data and solutions empower over 4,300 customers globally, including industry giants like Google, eBay, and Adidas, to make game-changing decisions that drive their digital strategies. In 2021, we went public on the New York Stock Exchange, and we continue to reach new heights! Come work alongside Similarwebbers across the globe who are bright, curious, practical and good people. We are looking for a Senior Fullstack Engineer with a strong backend orientation to join the development of our scalable, AI-powered product systems.

Responsibilities

Design and build scalable, maintainable backend services using NestJS (Node.js/TypeScript) and/or Python; Own API design, contracts, and versioning across services; Design and optimize data models, database schemas, and query performance; Implement authentication, authorization, and secure API integration patterns; Build reliable data-fetching layers, caching strategies, and async processing (queues, jobs, events); Lead backend technical decisions, code quality standards, and system architecture; Ensure system scalability, fault tolerance, and observability (logging, monitoring, alerting); Contribute to CI/CD pipelines and deployment practices for backend services; Collaborate on frontend applications built with React, TypeScript, and Vite, and contribute to API contracts from the consumer's perspective; Partner with frontend engineers to align on data shapes, performance, and UX constraints; Translate product requirements into robust, scalable technical solutions, working closely with product and design; Conduct high-quality code reviews and drive architectural discussions and best practices; Improve testing, observability, CI/CD, and system reliability across the team; Use AI coding tools effectively in daily development work (Cursor, Copilot, Claude, ChatGPT, etc.), critically evaluating and refining AI-generated code, especially for backend logic and data integrity; Design efficient personal/team workflows for AI-assisted development and contribute to engineering productivity through AI tooling and automation

Requirements

5+ years of fullstack engineering experience, with a strong backend focus; Strong proficiency in Node.js, TypeScript, and NestJS; Python proficiency also welcome (or equivalent backend framework); Solid working proficiency in React and modern frontend fundamentals (HTML, CSS); Experience designing scalable backend architectures and data models; Deep understanding of API design, authentication flows, and distributed system tradeoffs; Experience with relational and/or NoSQL databases, including query optimization; Strong understanding of system performance, reliability, and security best practices; Experience with testing methodologies (unit, integration, E2E) and observability tooling; Hands-on experience using AI development tools in daily workflows, with the ability to validate, debug, and improve AI-generated code; Understanding of prompt engineering for engineering workflows and the ability to work effectively in fast iteration environments; Strong product and technical intuition, with excellent communication and collaboration skills

Nice to have

Experience with data platforms, analytics products, or BI tools; large-scale data processing or query optimization; streaming/real-time data patterns; or integrating with LLM APIs

Benefits

Competitive compensation packages; Regular team outings and happy hours; Career Week; Personalized coaching; Ongoing learning solutions