Senior Node.js Engineer

🏢 Summary: Fullstack Engineer role focused on building and scaling a global data-driven insights platform using modern JavaScript technologies. The position involves developing backend and frontend services, designing scalable databases, and influencing system architecture. You will work on high-load systems, ensure code quality, and contribute to technical decisions and mentoring. 🗂️ Requirements: 5+ years of experience with JavaScript and Node.js, 3+ years of experience with TypeScript and React or Next.js, Hands-on experience with scalable backend systems, Experience designing SQL and NoSQL database schemas, Ability to optimize queries for high-load systems, Knowledge of web fundamentals and networking concepts, Understanding of OWASP security best practices, Experience with AWS cloud services, Experience writing unit, integration, and e2e tests, Professional proficiency in English 📃 Skills: JavaScript, Node.js, TypeScript, React, Next.js, REST, GraphQL, SQL, NoSQL, AWS, CORS, OWASP, Microservices, Serverless 🏢 Description: We’re building a data-driven insights platform used by professionals worldwide. Our mission is to turn complex data into actionable insights and empower teams to make better decisions. We value ownership, technical excellence, and collaboration . If you enjoy building scalable systems, mentoring engineers, and shaping software architecture, you’ll fit right in. 🎯 Your mission Develop and maintain backend and frontend services (REST/GraphQL APIs, React apps) Design scalable database schemas (SQL & NoSQL) and optimize queries for high-load systems Collaborate with product, design, and DevOps teams to deliver robust solutions Write clean, tested code (unit, integration, e2e) Influence architecture and technical decisions Mentor other developers and share best practices 📌 You should have 5+ years in JavaScript / Node.js 3+ years in TypeScript + React/Next.js Hands-on experience with scalable backend systems Knowledge of web fundamentals & networking (CORS, browser behavior) Understanding of security best practices (OWASP) Experience with cloud services (AWS preferred) Strong communication skills in English Ability to work independently and take ownership ✨ Nice to have Experience with microservices / serverless architectures Data pipelines, scraping, or data-heavy applications Team leadership or mentoring experience Exposure to AI/ML integrations 💡 Why join us High-impact role on a global data platform Work with modern technologies and best engineering practices Autonomy & ownership in your work Collaborative and experienced team Competitive employment package and benefits.

🏢 Summary: Backend Engineer role focused on designing and scaling real-time, cloud-based systems and APIs for an AI-powered consumer product. The position involves building reliable backend services, data pipelines, and infrastructure on AWS within a high-performing engineering team. You will collaborate with mobile and AI teams to deliver low-latency, scalable, and secure user experiences. 🗂️ Requirements: 2+ years backend development experience with Node.js and TypeScript, Strong knowledge of PostgreSQL including schema design and query optimization, Experience with Redis for caching and queue management, Hands-on experience with AWS services (EC2, RDS, Lambda, ECS, S3), Strong REST API design skills and real-time communication patterns, Understanding of scalability, concurrency, and distributed systems, Experience with Docker, Git workflows, and CI/CD automation, Knowledge of backend security and performance best practices 📃 Skills: Node.js, TypeScript, PostgreSQL, Redis, AWS, EC2, RDS, Lambda, ECS, S3, REST, WebSockets, SSE, Docker, Git, CICD 🏢 Description: Backend Engineer – Node.js, TypeScript, AWS For our client, a fast-growing team building a next-generation AI-powered consumer product, we are looking for an experienced Backend Engineer to help scale the systems powering real-time experiences, cloud synchronization, and intelligent APIs. This is not a founding role, but it is a highly impactful engineering position within a small, high-performing team focused on building world-class consumer technology products. About the role You will be responsible for designing, building, and scaling backend systems that support core product functionality — from real-time data pipelines to reliable cloud infrastructure and low-latency APIs. You’ll work closely with mobile and AI teams to deliver fast, scalable, and highly reliable user experiences. Responsibilities Backend Development Design and build RESTful APIs using Node.js and TypeScript (Express.js or Nest.js) Architect and maintain PostgreSQL databases, including schema design and query optimization Implement background jobs and queue systems using Redis for ingestion, summarization, and notifications Build and maintain caching layers (Redis, CDN, HTTP cache) to ensure low-latency performance Implement authentication, authorization, and data privacy best practices Add real-time capabilities using WebSockets and Server-Sent Events Build observability into services through logging, metrics, and tracing Deploy and manage backend services on AWS (EC2, ECS, RDS, S3, Lambda) Systems & Architecture Design clean, scalable, and maintainable service architectures Plan and execute safe database migrations and schema evolution strategies Ensure consistency and reliability across distributed systems Optimize system performance across I/O, CPU, and memory bottlenecks Build and maintain CI/CD pipelines and release automation workflows Contribute to infrastructure reliability, scalability, monitoring, and cost optimization Quality & Security Write unit, integration, and contract tests with clear quality standards Enforce linting, type safety, and static analysis within CI pipelines Conduct security reviews and dependency audits while following least-privilege principles Clearly document services, APIs, and important architectural trade-offs Requirements Must-have 2+ years of backend development experience with Node.js and TypeScript Strong understanding of PostgreSQL, including schema design, indexing, and query optimization Experience working with Redis for caching and queue management Hands-on experience with AWS services such as EC2, RDS, Lambda, ECS, and S3 Strong API design skills, including REST and real-time communication patterns Solid understanding of scalability, concurrency, and distributed systems Experience with Docker, Git workflows, and CI/CD automation Familiarity with security and backend performance best practices Nice to have Experience with GraphQL or gRPC Exposure to event-driven architectures or microservices Familiarity with observability tools such as OpenTelemetry, CloudWatch, or Sentry Experience building high-traffic consumer applications Example stack Backend: Node.js, TypeScript (Express.js / Nest.js), PostgreSQL, Redis Cloud: AWS (EC2, RDS, Lambda, ECS, S3, CloudWatch) Infrastructure: Docker, GitHub Actions, CI/CD

🏢 Summary: B2B contract role for a Mid/Senior Node.js Developer focused on building and maintaining backend systems such as SaaS platforms, cloud-native applications, microservices, and event-driven architectures. The position involves architectural decision-making, backend development, and close collaboration with QA and DevOps in international projects. Candidates will work with modern cloud environments and have real impact on system design and product development. 🗂️ Requirements: 4+ years of backend development experience, Strong knowledge of Node.js, Experience with TypeScript or JavaScript, Experience with SQL databases, Experience with NoSQL databases, Understanding of microservices architecture, Understanding of serverless architecture, Understanding of event-driven systems, Hands-on experience with GCP, AWS, or Azure, Ability to write clean and maintainable code, Experience with unit and integration testing, English level minimum B2 📃 Skills: Node.js, TypeScript, JavaScript, SQL, NoSQL, GCP, AWS, Azure, REST, Docker, Microservices, Serverless, Testing 🏢 Description: We are a software house delivering long-term projects for international clients , and we are looking for Mid / Senior Node.js Developers to join our team on a B2B contract . You will work on various backend-focused projects , such as SaaS platforms, cloud-native systems, microservices, and event-driven architectures. We match projects to your experience and technical preferences, and you will have a real impact on architecture and product development. Responsibilities design, develop, and maintain backend services using Node.js (TypeScript / JavaScript) implement new features and improve existing functionalities participate in technical and architectural decision-making refactor and optimize key components of the system ensure code quality through clean code practices and testing collaborate closely with developers, QA, and DevOps engineers Requirements 4+ years of experience in backend development strong knowledge of Node.js (TypeScript / JavaScript) experience with SQL and NoSQL databases good understanding of cloud-based architectures (microservices, serverless, event-driven systems) hands-on experience with at least one cloud provider ( GCP, AWS, or Azure ) ability to write clean, well-structured, and maintainable code proactive mindset and willingness to grow technically good communication skills and English level min. B2B Example Tech Stack (depends on the project) Node.js / TypeScript Cloud platforms: GCP, Azure or AWS REST APIs & asynchronous communication SQL & NoSQL databases Docker Unit and integration testing

🏢 Summary: Opportunity to architect and build a brand-new, high-scale, event-driven backend product from scratch using Node.js and TypeScript on AWS. The role focuses on designing resilient distributed systems, owning features end-to-end, and shaping technical direction in a high-growth environment. You will drive scalable architecture, ensure high code quality, and deploy production-ready services for global workloads. 🗂️ Requirements: 5+ years experience with Node.js and TypeScript in production environments, Advanced proficiency with AWS (Lambda, ECS, S3, RDS), Strong expertise in system design and scalability, Experience designing event-driven architectures, Experience with modern testing frameworks (Vitest, Jest, Playwright), Ability to build and deploy distributed systems, Experience with SQL and NoSQL databases, Knowledge of CI/CD practices using Docker and Kubernetes, Professional English proficiency 📃 Skills: Node.js, TypeScript, AWS, Lambda, ECS, S3, RDS, Vitest, Jest, Playwright, Docker, Kubernetes, SQL, NoSQL, Go, React, CI/CD 🏢 Description: We are looking for a high-impact engineer to architect a brand-new product from the ground up. In this role, you will bypass maintenance of legacy systems to design and develop high-scale, event-driven backend infrastructures. Operating at the intersection of technical rigor and rapid product evolution, you will thrive in an environment of high ambiguity where your architectural decisions define the roadmap. Core Responsibilities Architect and scale mission-critical backend services using Node.js and TypeScript . Design and implement high-performance APIs and sophisticated event-driven architectures on AWS . Engineer resilient, distributed systems capable of managing intensive global workloads. Own feature development end-to-end, navigating the lifecycle from initial design to production deployment. Partner closely with product and cross-functional engineering leads to drive technical innovation. Mentor the engineering squad and champion elite standards in code quality, security, and testing. Adapt and pivot technical strategies as the product scales and new challenges emerge. Technical Requirements 5+ years of hands-on experience deploying Node.js and TypeScript in high-stakes production environments. Advanced proficiency with the AWS ecosystem, including Lambda, ECS, S3, and RDS. Deep expertise in system design, scalability, and modern event-driven paradigms. Experience utilizing modern testing frameworks such as Vitest, Jest, or Playwright to ensure zero-defect deployments. Elite problem-solving skills with the ability to operate autonomously in a fast-moving hub. Professional fluency in English with a track record of driving cross-functional alignment. A high-velocity mindset suited for a dynamic, high-growth engineering culture. Additional Assets Hands-on experience with Go . Background in distributed systems or complex event-driven platforms. Experience integrating LLMs or modern AI tooling into production workflows. Practical knowledge of React or modern frontend frameworks. Deep understanding of SQL/NoSQL database optimization and CI/CD best practices via Docker and Kubernetes. The Offer Competitive compensation aligned with the top-tier Kraków tech market (UoP or B2B options). Flexible hybrid work model based in the heart of Kraków. Radical ownership and the unique opportunity to shape a global product from day one. Collaborative, English-speaking engineering environment within a stable, profitable firm with a long-term vision.

🏢 Summary: Frontend-focused role developing and maintaining scalable React applications with TypeScript, integrated with Node.js backend services and data pipelines. The position involves building production-grade, data-driven solutions, contributing to architecture decisions, and optimizing complex UI workflows. It offers work on a high-impact product within a modern TypeScript and React ecosystem. 🗂️ Requirements: Strong proficiency in React, Strong proficiency in TypeScript, Experience building large-scale production applications, Experience with Node.js and API integrations, Experience with data-driven applications, Understanding of modern frontend architecture, Knowledge of testing practices, Ability to work in cross-functional teams 📃 Skills: React, TypeScript, Node.js, APIs, Microservices, Snowflake, Testing, Architecture, Data, Pipelines 🏢 Description: ✅ Your responsibilities: Develop and maintain scalable React applications with TypeScript across the full frontend stack Collaborate closely with backend engineers, data teams, and product managers to deliver high-quality solutions Ensure type safety, code quality, and maintainability throughout the application Participate in design and architecture discussions, proposing improvements to frontend patterns and integrations Troubleshoot and optimize complex UI and data-intensive workflows Support knowledge sharing and mentor junior developers when needed 🧠 Our requirements: Strong proficiency in React and TypeScript , with experience building large-scale, production-grade applications Familiarity with Node.js backend development and integration with APIs or microservices Experience working with data-driven applications , ideally with Snowflake, data lakes, or pipelines Solid understanding of modern frontend architecture, testing, and best practices Ability to communicate effectively in a cross-functional, high-stakes environment Proactive, self-motivated, and capable of delivering high-quality solutions under tight timelines 🌟 What we offer: Opportunity to work on a premium, high-profile product with global business impact Exposure to a modern TypeScript/React ecosystem, integrated with backend Node.js services and advanced data pipelines Collaborative environment with experienced engineers and product leaders Career growth and technical mentorship in a cross-functional team Competitive employment package and benefits.

🏢 Summary: Full-Stack / Backend Developer role focused on building and maintaining scalable applications and REST APIs that support client products. The position involves developing new integrations, enhancing existing backend and frontend systems, and improving platform performance and reliability. You will contribute to architecture improvements and work within a cloud-based environment. 🗂️ Requirements: Minimum 3 years commercial experience, Experience with Java, Experience with Spring Boot, Experience with AWS, Experience with MongoDB, Experience with PostgreSQL, Experience with React.js, Experience designing REST APIs, Knowledge of backend architecture, Experience with cloud environments, Understanding of clean code principles, Experience working in Agile environment 📃 Skills: Java, SpringBoot, AWS, MongoDB, PostgreSQL, React, REST, Agile, Cloud, Architecture 🏢 Description: We are looking for an experienced Full-Stack / Backend Developer to join our team and help build scalable applications and APIs supporting our clients’ products. You will work on both backend and frontend solutions, contributing to product development, system improvements, and ongoing platform stability. Your Responsibilities Develop new APIs to support client integrations and business features. Maintain and enhance existing backend and frontend applications. Fix bugs and improve application performance and reliability. Upgrade and support operational aspects of the platform. Identify opportunities to improve product quality, architecture, and development processes. Collaborate with developers, product teams, and stakeholders to deliver high-quality solutions. Participate in code reviews and contribute to best engineering practices. Required Skills Minimum 3 years of commercial experience with: Java Spring Boot AWS MongoDB PostgreSQL React.js Experience designing and developing REST APIs. Knowledge of backend architecture and modern web applications. Experience working with cloud-based environments (AWS). Understanding of software development best practices and clean code principles. Ability to work in an Agile development environment.

🏢 Summary: Lead Software Engineer role focused on building scalable, secure, and high-performance full-stack applications for enterprise and public sector clients. The position involves designing modern frontend and backend solutions, developing APIs and microservices, and supporting cloud-based CI/CD environments. The role also includes technical leadership and mentoring while ensuring best practices in security and performance. 🗂️ Requirements: Strong experience with JavaScript, Strong experience with TypeScript, Backend development experience with Node.js or Python, Experience with modern frontend frameworks, Knowledge of APIs and microservices, Experience with cloud platforms (AWS, Azure, or GCP), Familiarity with CI/CD pipelines, Experience with testing frameworks, Understanding of security best practices, Understanding of performance optimization best practices, Experience mentoring developers or leading technical initiatives 📃 Skills: JavaScript, TypeScript, Node.js, Python, React, Vue, Angular, REST, GraphQL, Microservices, APIs, AWS, Azure, GCP, CICD, Testing, Security, Performance 🏢 Description: International company delivering advanced internet connectivity solutions is looking for a Lead Software Engineer to help build scalable, secure, and high-performance digital products used by enterprise and public sector clients. Your responsibilities 🚀 Designing and developing modern full-stack applications Building scalable front-end solutions (React, Vue, Angular) Developing backend services and APIs (REST / GraphQL) Creating reusable components and microservices Supporting CI/CD, testing, monitoring, and automation Collaborating with Product and Design teams Mentoring engineers and supporting technical decisions Must have ✅ Strong experience with JavaScript / TypeScript Backend development experience (Node.js preferred or Python) Experience with modern frontend frameworks Knowledge of APIs, microservices, and cloud platforms (AWS, Azure, GCP) Familiarity with CI/CD and testing frameworks Understanding of security and performance best practices Experience mentoring developers or leading technical initiatives Nice to have ⭐ Experience with AI-driven tools Knowledge of design systems or distributed systems Advanced security knowledge

🏢 Summary: Senior Fullstack Software Engineer role focused on building scalable, cloud-native applications with a strong backend emphasis (70% backend, 30% frontend). The position involves designing distributed, event-driven systems on AWS, developing REST APIs, and contributing across the full stack using Node.js, TypeScript, React, and Next.js. The engineer will drive architectural decisions, scalability, and technical direction while collaborating with cross-functional teams in a US-aligned remote environment. 🗂️ Requirements: Strong experience as Senior Software Engineer in product-focused environments, Advanced backend development with Node.js and TypeScript, Experience building and consuming REST APIs, Frontend development experience with React and TypeScript, Experience with AWS or other cloud platforms, Strong knowledge of distributed and scalable system design, Experience with MySQL and PostgreSQL databases, Experience with event-driven architectures, Experience with queuing or messaging systems, Ability to write clean, maintainable, scalable code, Strong debugging and problem-solving skills, Availability to work overlapping US hours 📃 Skills: Node.js, TypeScript, React, Next.js, AWS, REST, MySQL, PostgreSQL, SQL, APIs, Microservices, Event-driven, Messaging, Queues, Cloud, Distributed-systems 🏢 Description: Fullstack Senior Software Engineer Location: Remote We are looking for a talented Senior Fullstack Software Engineer to join a high-performing product engineering team focused on building scalable, modern cloud-native applications. This role is best suited to an experienced engineer who is stronger on the backend (approximately 70% backend / 30% frontend) and enjoys designing robust distributed systems while still being comfortable contributing across the full stack. You will play a key role in shaping technical direction, building scalable event-driven platforms, and contributing to product thinking - not just delivering code. We are looking for someone with strong ownership, accountability, and the ability to think about the wider business and customer impact of the solutions they build. This position requires alignment with US-based teams, and so the working hours must overlap. What You'll Be Doing Designing, building, and maintaining scalable backend services using Node.js and TypeScript Developing and supporting modern frontend applications using React and Next.js Building robust RESTful APIs and backend integrations Contributing to distributed, cloud-native systems running on AWS Designing and implementing event-driven architectures and queue-based systems Working with SQL databases including MySQL and PostgreSQL Driving engineering best practices, scalability, reliability, and performance improvements Collaborating closely with Product, Engineering, and stakeholders to shape technical solutions Taking ownership of features and systems throughout the full software lifecycle Mentoring engineers and contributing to technical discussions and architectural decisions Required Skills & Experience Strong experience as a Software Engineer / Senior Software Engineer in modern product-focused environments Excellent backend development experience with: Node.js TypeScript REST APIs React TypeScript Experience building applications in AWS cloud environments (or other cloud platforms) Strong understanding of scalable and distributed system design MySQL PostgreSQL Proven experience building event-driven architectures and working with queuing/messaging systems (highly important) Ability to write clean, maintainable, and scalable code Strong problem-solving and debugging skills What We're Looking For Strong product mindset - someone who thinks beyond just delivering tickets and understands the "why" behind engineering decisions Ownership and accountability for technical delivery and outcomes Ability to contribute to architectural direction and scalability initiatives Comfortable working in fast-paced, collaborative engineering environments Passion for building high-quality, scalable software products Strong communication and stakeholder collaboration skills

🏢 Summary: Senior Backend Engineer role focused on designing, building, deploying, and maintaining scalable backend systems using TypeScript and Node.js in a cloud environment. The position involves developing microservices on AWS, shaping system architecture across platforms, and ensuring production reliability for international users. Strong emphasis on clean architecture, testing, and infrastructure as code. 🗂️ Requirements: 5+ years backend development experience in production environments, Expert hands-on experience with TypeScript and Node.js, Strong knowledge of software engineering principles, testing, data structures, and algorithms, Experience designing and developing REST APIs, Experience with event-driven architecture, Experience building and maintaining microservices, Hands-on experience with AWS cloud services, Experience with Infrastructure as Code using Terraform, Experience with CI/CD pipelines and related tools, Strong knowledge of PostgreSQL and DynamoDB, Proficiency in OO design patterns, SOLID principles, and Clean Code, Computer Science degree, Experience working with Agile methodologies such as SCRUM or Kanban 📃 Skills: TypeScript, JavaScript, Node.js, AWS, Terraform, CircleCI, Docker, Datadog, PostgreSQL, DynamoDB, REST, CICD, Microservices, OOP, SOLID, Algorithms, DataStructures, SCRUM, Kanban 🏢 Description: About the role You will need to be an expert in backend development with a thorough understanding of the technologies involved. Strong backend skills where you can demonstrate your ability to apply these technologies, as well as deploy and maintain them will be crucial to success. Technologies we work with: Typescript, JavaScript, Node.js, REST APIs, AWS, Terraform Responsibilities: Designing, writing, testing functionalities for a backend system written in TypeScript, Node.js Deploying and maintaining microservices in AWS using Terraform Design software architecture between backend, frontend and mobile apps Maintaining system on production used by consumers from several European countries Debugging issues Scoping and assessing the complexity of features Participating in sprint planning, daily sprints and meetings with product owners for grooming new features Recruiting and mentoring team members Collaborating with other team members and teams that depend on the functionalities that you develop Required qualifications: 5+ years of production software development experience in backend Strong understanding of software engineering principles, testing, data structures and algorithms Expert hands-on experience in technologies such as Typescript / Node.js Experience in developing Cloud and Infrastructure solutions with AWS and CI/CD processes supported by tools like Terraform, CircleCI, Docker, Datadog, etc. Strong knowledge of DBMS like PostgreSQL, DynamoDB Expertise in REST APIs, Experience in event driven architecture Proficiency in OO design patterns, SOLID principles, Clean Code and solving architectural problems Computer Science degree Experience working with Agile methodologies such as SCRUM and/or Kanban Good communication and collaboration skills Self-motivation, proactive attitude Proficiency in English Nice to have: Exposure to frontend development in React Working experience with one of the object-oriented and/or functional languages such as C#, Python Java, Golang, Kotlin

🏢 Summary: Remote Senior Backend Node.js Developer role focused on building and scaling an event-driven microservices trading platform. The position involves end-to-end development, collaborating across product, QA, and DevOps to deliver high-performance, scalable trading solutions. B2B contract with overlap required with NYC working hours. 🗂️ Requirements: Bachelor’s Degree in Computer Science or related field, 3-5 years professional web application development experience, Expert-level Node.js knowledge, Expert-level TypeScript knowledge, Experience with distributed systems, Experience with Apache Kafka, Redis, Kubernetes, MongoDB, Experience with automated unit testing and TDD, Strong understanding of performance optimization and computational complexity, Knowledge of algorithms and design patterns, Fluent English (written and spoken) 📃 Skills: Node.js, TypeScript, Kafka, Redis, Kubernetes, MongoDB, Microservices, TDD, Algorithms, DesignPatterns, Web, DistributedSystems 🏢 Description: We are looking for a performance-driven backend Senior Node.js Developer who can help us bring our client's trading solutions to the next level of functionality, scalability, and user experience. They are actively developing a new event-driven microservices architecture to form a foundational platform for delivering new trading applications. You will be responsible for delivering software end-to-end , from liaising with product managers and designers, to coordinating across international development teams on engineering and architecture to working with QA and DevOps teams - all ultimately to deliver a quality, innovative product to the traders and investors who depend on the platform every day. Requirements: Fluent English language [both written and spoken] Education: at least Bachelor's Degree, preferably in Computer Science 3-5 years' professional web application development experience Expert-level Node.js and TypeScript knowledge, and curiosity to learn more Broad knowledge of web platform and technologies Superior analytical and problem-solving ability Effective communication skills to work with different teams across an international company Experience with modern distributed systems and infrastructure technologies, including Apache Kafka, Redis, Kubernetes, and MongoDB Automated unit testing and test-driven development Robust understanding of performance issues, computational complexity, and code optimization. Familiarity and implementation of industry-standard algorithms and design patterns Proactive and team player who can deliver in a high-pressure demanding environment Nest.js – nice to have Offer details: 100% remote job preferrably at least 4-5 hours overlap with NYC working hours B2B contract rate up to 50 USD/h net Don't hesitate and apply now!