Senior Software Engineer
⚲ Warszawa
250 000 - 300 000 PLN netto (B2B)
Wymagania
- AWS
- Event-Driven Architecture
- Kafka
- Java
Opis stanowiska
Join a global e-commerce technology organisation serving millions of customers across multiple international markets.
As a Senior Backend Engineer, you will become part of a team responsible for one of the company's most critical customer-facing domains. The platform supports customer subscriptions, plans, and purchasing journeys used daily by millions of users.
This is not a maintenance role. The team is actively transforming a mission-critical domain, modernising legacy systems, reducing technical debt, and building the next generation of scalable services that will support future growth.
You will play a key role in migrating core functionality from a monolithic architecture to modern microservices while helping shape the future architecture of a global platform.
What You'll Do
Build & Scale Core Services
• Design, develop, and maintain scalable backend services within a distributed microservices architecture.
• Build reliable systems supporting millions of customer interactions.
• Improve performance, reliability, and scalability across critical customer-facing services.
Drive Modernisation
• Lead the migration of key business domains from monolithic systems to modern microservices.
• Reduce technical debt and improve long-term maintainability.
• Design solutions that support future platform growth.
Shape Architecture
• Participate in architecture discussions and technical decision-making.
• Design orchestration layers supporting complex customer journeys and business processes.
• Help define engineering standards and best practices.
Work with Event-Driven Systems
• Build and operate services powered by event-driven architectures.
• Work extensively with Kafka and real-time lifecycle events.
• Design resilient and observable distributed systems.
Raise Engineering Standards
• Conduct code reviews and support other engineers through technical guidance.
• Promote best practices across software development, testing, deployment, and observability.
• Contribute to a strong culture of ownership and continuous improvement.
AI-Powered Engineering
• Use modern AI tools and coding agents throughout the software development lifecycle.
• Leverage AI for onboarding, architecture exploration, implementation, testing, debugging, and productivity improvements.
• Apply engineering judgement to validate, verify, and safely integrate AI-generated outputs.
What We're Looking For
Backend Engineering Expertise
• 5+ years of professional backend engineering experience.
• Strong experience designing and operating microservices architectures.
• Experience modernising legacy systems and decomposing monoliths.
• Solid understanding of distributed systems and scalable backend design.
Technical Stack
• Commercial experience with Go (Golang), Java, Kotlin or Scala
• Engineers coming from a JVM background should be open to working in a Go-driven environment.
• Hands-on experience with:• Kafka or similar event-streaming technologies
• PostgreSQL
• Docker
• Kubernetes
• CI/CD pipelines
Product & Ownership Mindset
• Comfortable owning solutions from idea through production.
• Strong problem-solving skills and ability to make technical trade-offs.
• Experience collaborating with product, business, and engineering stakeholders.
AI Fluency
• Practical experience using AI coding assistants such as Claude Code, Cursor, Copilot, or similar tools.
• Understanding of how context, prompts, constraints, and validation influence AI-generated outputs.
• Ability to critically review and verify AI-generated solutions.
Nice to Have
• Experience with subscription-based products.
• Experience in e-commerce environments.
• GraphQL knowledge.
• Familiarity with DDD, TDD, and BDD practices.
What We Offer
• Opportunity to build systems used by millions of customers globally.
• High-impact engineering work with significant architectural ownership.
• International collaboration across distributed engineering teams.
• End-to-end ownership from idea to production.
• Hybrid working model (3 days per week in the Warsaw office).
• B2B cooperation model.
• 30 days of paid annual leave.
• Modern office located in Warsaw city centre.
• Continuous learning and professional growth opportunities.
As a Senior Backend Engineer, you will become part of a team responsible for one of the company's most critical customer-facing domains. The platform supports customer subscriptions, plans, and purchasing journeys used daily by millions of users.
This is not a maintenance role. The team is actively transforming a mission-critical domain, modernising legacy systems, reducing technical debt, and building the next generation of scalable services that will support future growth.
You will play a key role in migrating core functionality from a monolithic architecture to modern microservices while helping shape the future architecture of a global platform.
What You'll Do
Build & Scale Core Services
• Design, develop, and maintain scalable backend services within a distributed microservices architecture.
• Build reliable systems supporting millions of customer interactions.
• Improve performance, reliability, and scalability across critical customer-facing services.
Drive Modernisation
• Lead the migration of key business domains from monolithic systems to modern microservices.
• Reduce technical debt and improve long-term maintainability.
• Design solutions that support future platform growth.
Shape Architecture
• Participate in architecture discussions and technical decision-making.
• Design orchestration layers supporting complex customer journeys and business processes.
• Help define engineering standards and best practices.
Work with Event-Driven Systems
• Build and operate services powered by event-driven architectures.
• Work extensively with Kafka and real-time lifecycle events.
• Design resilient and observable distributed systems.
Raise Engineering Standards
• Conduct code reviews and support other engineers through technical guidance.
• Promote best practices across software development, testing, deployment, and observability.
• Contribute to a strong culture of ownership and continuous improvement.
AI-Powered Engineering
• Use modern AI tools and coding agents throughout the software development lifecycle.
• Leverage AI for onboarding, architecture exploration, implementation, testing, debugging, and productivity improvements.
• Apply engineering judgement to validate, verify, and safely integrate AI-generated outputs.
What We're Looking For
Backend Engineering Expertise
• 5+ years of professional backend engineering experience.
• Strong experience designing and operating microservices architectures.
• Experience modernising legacy systems and decomposing monoliths.
• Solid understanding of distributed systems and scalable backend design.
Technical Stack
• Commercial experience with Go (Golang), Java, Kotlin or Scala
• Engineers coming from a JVM background should be open to working in a Go-driven environment.
• Hands-on experience with:• Kafka or similar event-streaming technologies
• PostgreSQL
• Docker
• Kubernetes
• CI/CD pipelines
Product & Ownership Mindset
• Comfortable owning solutions from idea through production.
• Strong problem-solving skills and ability to make technical trade-offs.
• Experience collaborating with product, business, and engineering stakeholders.
AI Fluency
• Practical experience using AI coding assistants such as Claude Code, Cursor, Copilot, or similar tools.
• Understanding of how context, prompts, constraints, and validation influence AI-generated outputs.
• Ability to critically review and verify AI-generated solutions.
Nice to Have
• Experience with subscription-based products.
• Experience in e-commerce environments.
• GraphQL knowledge.
• Familiarity with DDD, TDD, and BDD practices.
What We Offer
• Opportunity to build systems used by millions of customers globally.
• High-impact engineering work with significant architectural ownership.
• International collaboration across distributed engineering teams.
• End-to-end ownership from idea to production.
• Hybrid working model (3 days per week in the Warsaw office).
• B2B cooperation model.
• 30 days of paid annual leave.
• Modern office located in Warsaw city centre.
• Continuous learning and professional growth opportunities.
🔍 Dekoder Ogłoszenia
🔴
This is not a maintenance role.
Chociaż nie jest to stricte rola utrzymaniowa, prawdopodobnie nadal będziesz musiał zajmować się istniejącym kodem i rozwiązywać problemy w starszych systemach.
🔴
modernising legacy systems, reducing technical debt
Oznacza to pracę z przestarzałym kodem i potencjalnie frustrującymi problemami, które wymagają gruntownych zmian.
🔴
building the next generation of scalable services
Może to oznaczać, że obecne systemy nie są wystarczająco skalowalne, a Ty będziesz musiał rozwiązywać problemy wynikające z tej niedoskonałości.
🔴
Lead the migration of key business domains from monolithic systems to modern microservices.
Jest to ambitne zadanie, które może oznaczać znaczną presję czasu i konieczność radzenia sobie z nieprzewidzianymi trudnościami podczas migracji.
🟡
Participate in architecture discussions and technical decision-making.
Chociaż brzmi to jak duży wpływ, rzeczywisty wpływ może zależeć od dynamiki zespołu i hierarchii firmy.