JustJoin.IT Praca zdalna Senior New

Fullstack Engineer (AI, Distributed Systems, Automation)

Web Impact

⚲ Kraków

20 000 - 28 000 PLN netto (B2B)

Wymagania

  • Next.js
  • React
  • Node.js
  • TypeScript
  • AI Tools
  • Distributed systems
  • Rust
  • Elixir

Opis stanowiska

At Web Impact, we’re more than just an email marketing agency and digital solutions provider. We build cutting-edge, socially impactful products that redefine how businesses operate in the digital world. We’re looking for a frontend-leaning Fullstack Engineer who enjoys building complex systems, integrating external services, and leveraging AI tools to speed up development and automate workflows. If you’re excited about combining modern frontend development with AI-driven workflows and automation tools like Claude Code, Cursor, and LLM frameworks, this one is for you. What You’ll Do • Own and deliver end-to-end features across SaaS products and internal tools • Build modern, high-performance frontends using Next.js and React.js • Develop scalable backend services using Node.js / NestJS • Design and integrate APIs (REST, WebSockets, external services) • Build and maintain automation workflows and background jobs • Work with async systems, queues, and event-driven architectures • Integrate third-party services with real-world constraints (rate limits, retries, auth flows) • Use AI tools to improve development speed, testing, and automation • Collaborate directly with product, data, and leadership teams AI & Automation This role includes working with modern AI tooling and automation systems, with a strong focus on speed, ownership, and execution: • Using tools like Claude Code, Cursor, and OpenAI SDK in daily development • Building AI-driven workflows and integrations quickly and iteratively • Automating repetitive processes (data handling, content, integrations) • Applying LLMs in production with a pragmatic, results-first approach • Taking full ownership of problems - from idea to production • Shipping fast, testing in real conditions, and iterating based on outcomes • Being accountable for delivery - not just writing code, but making things work end-to-end • Prioritizing execution over perfection - speed is key What We’re Looking For • 3+ years of professional full-stack experience • Strong frontend skills in React.js / Next.js • Solid backend experience with Node.js (NestJS preferred) • Experience integrating external APIs (auth, pagination, retries, rate limits) • Experience working with async processing, queues, and background jobs • Hands-on experience with modern AI tools (OpenAI, Claude, Cursor, etc.) • Good SQL skills (PostgreSQL preferred) • Understanding of building reliable systems (error handling, retries, observability) • Strong communication skills and ability to work cross-functionally • Fluent in English and Polish Nice to Have • Experience with Rust (async, Tokio, Axum) • Experience with Elixir (Phoenix LiveView, GenServer) • Understanding of distributed systems and architectures • Experience with multi-region deployments and geo-distributed infrastructure • Experience building systems with high parallelism (a large number of workers processing jobs concurrently) • Familiarity with distributed databases and data consistency trade-offs • Experience with multi-tenancy architectures (tenant isolation, scaling strategies) • Experience working with high-throughput event pipelines Our Tech Stack • Frontend: Next.js, React.js • Backend: Node.js, NestJS, Golang, Elixir, Rust • Data: PostgreSQL, BigQuery, ClickHouse • Infra: AWS, Fly.io, Google Cloud, DigitalOcean • Queues & Workers: LavinMQ, BullMQ, Kafka • CI/CD: GitLab CI • AI/ML & Automation: Proprietary GenAI models, OpenAI, Claude, internal tooling • Integrations: REST, gRPC, WebSockets, external APIs with rate limits Why Join Us? • Work on high-scale SaaS systems processing hundreds of millions of events daily, with real-time pipelines and data-heavy workloads. • Ownership from day one - influence architecture, technology choices, and product direction. • Collaborate with world-class engineers, AI specialists, and PMs. • Innovation-first culture - explore cutting-edge frameworks and architectures. • Fast execution, minimal bureaucracy, no unnecessary meetings • Opportunity to work with modern AI tooling in production • Competitive senior-level compensation and career growth. • Social impact - contribute to automation products that empower businesses and communities. Our Streamlined Hiring Process • Initial call • Technical deep dive with our team • Decision