Senior QA Backend Engineer

🏢 Summary: Senior QA Backend Engineer role focused on validating distributed microservice architectures, backend integrations, and event-driven systems in an Agile environment. The position involves deep backend testing, log and trace analysis, API and database validation, and coordination across multiple development squads. Hybrid work model with mandatory on-site presence in Warsaw and English communication at C1 level. 🗂️ Requirements: 5+ years of commercial end-to-end software testing experience, Strong analytical test design skills, Architectural understanding of web and mobile applications, Experience with Jira, Experience with Xray, Experience with TestRail, Experience with YouTrack, Experience in Agile environments, Experience with AWS SNS/SQS or similar queue systems, API testing experience, SQL proficiency, English C1 📃 Skills: AWS, SNS, SQS, Postman, Swagger, SQL, Jira, Xray, TestRail, YouTrack, Scrum, Kanban, REST, HTTP, ISTQB 🏢 Description: co.brick talents — powered by AI, powered by people. We are seeking a highly analytical Senior QA Backend Engineer to orchestrate the validation of complex, multi-service architectures and event-driven data flows. In this position, you will heavily focus on backend testing—analyzing system logs, tracing service-to-service communication, and validating backend message handling across modern cloud infrastructure. Operating within an Agile environment, you will bridge communication gaps between multiple development teams, identify critical system paths, and ensure end-to-end product stability. Details Seniority: Senior (5+ years of software testing experience). Allocation: Full-time (1 FTE). Rate: 65-80 pln/h B2B Start Date: ASAP. Languages: English at a C1 level (essential for cross-team coordination). Work Model & Location: Hybrid. Weekly on-site presence required on Thursdays at the client's office in Warsaw (Mokotów) , plus mandatory on-site attendance for periodic PI Planning sessions. Responsibilities Backend & Microservices Validation: Deep-dive into testing distributed microservice architectures, verifying that data flows, async states, and transactions resolve correctly across isolated components. Event-Driven & Integration Testing: Map and validate messaging architectures, specifically focusing on event queues, data ingestion routing, and message pub/sub lifecycles. Log & Trace Analysis: Proactively parse server-side logs, monitor internal API gateways, and evaluate database persistence to uncover anomalies before they reach production. Test Orchestration: Strategy, plan, and execute rigorous integration, system, usability, and E2E testing suites, while guiding cross-functional teams through complex User Acceptance Testing (UAT) gates. Cross-Squad Alignment: Drive alignment and foster communication between distinct development squads to pinpoint high-risk areas, eliminate technical silos, and improve platform reliability. Requirements Core QA Competencies 5+ years of verified commercial experience in end-to-end software testing with strong analytical test design capabilities. Solid architectural understanding of web and mobile application structures. High proficiency with test and defect management tooling (e.g., Jira, Xray, TestRail, YouTrack ). Experienced operating within agile software development lifecycles (Scrum/Kanban). Backend & Systems Stack Strong experience tracking asynchronous integrations via AWS SNS/SQS or similar queue infrastructures. Hands-on command over API testing toolsets ( Postman, Swagger , etc.). Proficient with SQL databases (writing queries, validating schema states, and isolating data anomalies). Nice to Have (Pluses) Domain experience inside Card Payments or Card Management Systems (Fintech/Banking) . Hands-on familiarity with test automation structures for mobile or web surfaces. Deep architectural understanding of REST API standards, HTTP status protocols, and API contract testing. Professional QA certifications ( ISTQB Foundation and/or ISTQB Advanced Level Test Analyst ).

🏢 Summary: QA Backend Engineer role focused on testing complex backend systems, microservice architectures, and distributed integrations in a hybrid work model. The position involves end-to-end validation, API and integration testing, defect management, and collaboration with multiple development teams in Agile environments. The offer includes B2B cooperation, private healthcare, life insurance, and access to learning platforms. 🗂️ Requirements: 5+ years of Software Tester experience, Backend-focused testing experience, Experience with microservice architectures, Knowledge of test design techniques, Experience with integration, system, E2E, and UAT testing, Understanding of asynchronous and event-driven systems, Experience with AWS SNS/SQS, Knowledge of SDLC, Experience with Jira or YouTrack, Experience with TestRail or Xray, Experience with Postman and Swagger, SQL database experience, Ability to analyze logs and trace requests, Experience in Agile environments, Strong analytical and problem-solving skills, Strong communication and collaboration skills 📃 Skills: QA, Testing, Microservices, AWS, SNS, SQS, SQL, Postman, Swagger, Jira, YouTrack, TestRail, Xray, Agile, SDLC, REST, HTTP, UAT, E2E 🏢 Description: Location: Hybrid work model (Warsaw, Mokotów). Onsite presence required on Thursdays and during PI Planning sessions Availability: ASAP / within 1 month Contract Type: B2B via Experis About the Role We are looking for a QA Backend Engineer to join a dynamic product development environment. In this role, you will be responsible for ensuring the quality, stability, and reliability of complex applications and integrations. You will work closely with multiple development teams, validating end-to-end business processes and backend flows across distributed systems and microservice-based architectures. Responsibilities - Plan and execute integration, system, and usability testing activities - Participate in End-to-End (E2E) and User Acceptance Testing (UAT) - Validate complex backend processes across multiple microservices and integrations - Analyze test results and identify potential risks affecting product quality and stability - Work closely with developers to understand critical business and technical flows - Analyze logs, trace requests, and validate data flow across services - Support defect management and resolution activities - Build strong cooperation with multiple development teams - Collaborate with cross-functional and cross-team stakeholders to continuously improve product quality - Contribute to testing strategy, planning, execution, and evaluation throughout the software development lifecycle Requirements - At least 5 years of experience as a Software Tester - Experience in planning, analyzing, executing, and evaluating tests - Strong knowledge of common test design techniques - Strong analytical and problem-solving skills - Strong backend-focused testing experience - Experience testing microservice-based architectures across multiple services - Understanding of asynchronous and event-driven systems - Experience with AWS SNS/SQS integrations and messaging flows - Understanding of mobile and web-based applications - Good understanding of the Software Development Lifecycle (SDLC) - Experience with defect management tools such as Jira or YouTrack - Experience with test management tools such as TestRail or Xray - Experience using API testing tools such as Postman and Swagger - Experience working with SQL databases - Ability to analyze logs, trace requests, and validate data flows - Experience working in Agile environments - Strong communication and collaboration skills - Ability to work effectively with multiple development teams - Highly motivated team player with a proactive attitude Nice to Have - Experience with test automation for mobile and web applications - Knowledge of REST API standards, HTTP protocols, and API contract validation - Experience within card payments or card management domains - ISTQB Foundation Level and/or ISTQB Advanced Test Analyst certification Offer - Multisport card - Private healthcare (Medicover) - Access to an e-learning platform - Group life insurance

🏢 Summary: Mid/Senior QA Backend Engineer role focused on backend, integration, system, and API testing in microservice-based environments. The position involves validating complex backend flows, collaborating with multiple development teams, and ensuring product stability in Agile projects. Hybrid work model in Warsaw with a B2B contract and ASAP availability. 🗂️ Requirements: 3+ years of experience as a software tester, Experience in planning, analysis, execution and evaluation of tests, Knowledge of common test design techniques, Strong backend-focused testing experience, Experience testing microservice-based architectures, Understanding of asynchronous and event-driven systems, Experience with AWS SNS/SQS integrations, Knowledge of software development lifecycle, Experience with defect management tools, Experience with test management tools, Experience with API testing tools, Experience with SQL databases, Ability to analyze logs and trace requests, Experience in Agile testing projects, English level B2/C1, Strong cross-team collaboration skills 📃 Skills: QA, Backend, Microservices, AWS, SNS, SQS, Jira, YouTrack, TestRail, Xray, Postman, Swagger, SQL, Agile, API, REST, HTTP, ISTQB 🏢 Description: For one of our clients, we are looking for a QA Backend Engineer (m/f/n). Technical Skills: At least 3+ years of experience as software tester Highly motivated team player with strong communication skills Working experience in planning, analysis, execution and evaluation of tests Working experience and knowledge of common test design techniques Strong test analytics skills Understanding of mobile and web-based applications Strong backend-focused testing experience Experience testing microservice-based architectures across multiple services Understanding of asynchronous and event-driven systems Experience with AWS SNS/SQS based integrations and messaging flows Understanding of software development lifecycle Knowledge of defect management tools like: Jira, YouTrack etc. Knowledge of test management tools like: TestRail, Xray etc . Experience of API testing tools: Postman, Swagger etc . Experience with SQL databases Ability to analyze logs, trace requests and validate data flow across services Experience in Agile Testing in projects Strong cross-team collaboration and communication skills while working with multiple development teams Seniority Mid/Senior English B2/C1 Nice to have: Experience in automation test of mobile and web applications is an advantage Knowledge of REST API standards, HTTP protocols and API contract validation is an advantage Knowledge and experience in card payments/card management subject matter is an advantage ISTQB Foundation Level and/or ISTQB Advanced Level Test Analyst certification is an advantage Scope of Responibilities: Plan and execute integration, system and usability testing Taking part of E2E and UAT testing Validate complex backend flows across multiple microservices and integrations Work with the developers to understand the critical paths and ensure product stability Build better cooperation with other Dev Teams Collaborate closely with cross-functional and cross-team stakeholders to improve overall product quality Offer: Rate: 85 PLN/H net + VAT B2B contract via SHIMI Location: Warsaw - hybrid work Availability: ASAP

🏢 Summary: Senior Backend QA Engineer role focused on ensuring quality, reliability, and security of .NET-based backend services, APIs, and SQL databases in a hybrid Kraków setup. The position involves designing and executing backend test strategies, validating data integrity, and integrating automated tests into CI/CD pipelines. This role targets mission-critical systems within an international environment. 🗂️ Requirements: Minimum 5 years experience as Software Tester or QA Engineer, Hands-on experience testing .NET backend services, At least 2 years experience in API testing, Strong SQL skills including complex queries and stored procedures, Experience with CI/CD pipelines, Experience with Jenkins or Azure DevOps, Ability to design and execute backend test cases, Experience with defect tracking and debugging backend issues, Fluency in English 📃 Skills: .NET, SQL, REST, Postman, Swagger, Jenkins, Azure, JMeter, k6, CI/CD, TDD 🏢 Description: Ignite quality assurance excellence — elevate backend systems to new standards! Kraków-based opportunity with hybrid work model (up to 3 remote days per week). As a Senior Backend QA Engineer , you will be working for our client, a global leader in delivering innovative backend solutions. You will play a pivotal role in ensuring the robustness, reliability, and security of backend services and APIs built on .NET and SQL, contributing directly to the seamless operation and trustworthiness of their digital platforms. This is an exciting opportunity to impact mission-critical systems and advance your career within a dynamic, international environment. Your main responsibilities: Design, develop, and execute comprehensive test cases for backend services, APIs, and databases. Perform integration, regression, and system testing on .NET backend applications. Validate data integrity and business logic within SQL databases, including stored procedures and complex queries. Test and validate RESTful APIs using tools such as Postman or Swagger. Analyze system requirements and craft effective test strategies to ensure full coverage. Identify, document, and track defects, collaborating closely with developers to facilitate rapid resolution. Contribute to the continuous improvement of QA processes and best practices. Support CI/CD pipelines by integrating automated tests and assisting ongoing deployment activities. You're ideal for this role if you have: At least 5 years of experience as a Software Tester or QA Engineer, preferably focused on backend or API testing. Strong hands-on experience testing .NET backend code and services. 2+ years of practical API testing and validation experience. Proficiency in SQL, including the ability to craft and execute complex queries and test stored procedures. Solid understanding of CI/CD pipelines and experience with tools like Jenkins or Azure DevOps. Knowledge of software engineering best practices, including SOLID principles, TDD, and data validation. Experience analyzing logs and debugging backend issues. It is a strong plus if you have: (optional) Experience with performance and load testing tools such as JMeter or k6. Knowledge of microservices architecture and cloud platforms like Azure. Understanding of security testing for backend services. Language Required for the role: Fluency in English (good command). We offer you: ITDS Business Consultants is involved in various, innovative, and professional IT projects for international companies in the financial industry in Europe. We offer an environment for professional, ambitious, and driven people. The offer includes: Stable and long-term cooperation with very good conditions Enhance your skills and develop your expertise in the financial industry Work on the most strategic projects available in the market Define your career roadmap and develop yourself in the best and fastest possible way by delivering strategic projects for different clients of ITDS over several years Participation in Social Events, training, and work in an international environment Access to an attractive Medical Package Access to Multisport Program #MAKEYourCareerBETTER Interested? Apply now and include your CV (preferably in English) along with a statement confirming your consent to the processing and storage of your personal data.

🏢 Summary: Senior Backend Engineer role focused on designing and scaling a high-throughput, event-driven platform. The position centers on building and optimizing large-scale event processing services and APIs in distributed systems. It involves solving complex scalability and reliability challenges in a massive-scale environment. 🗂️ Requirements: Senior-level experience in backend development, Strong Python expertise, Experience scaling message queue systems, Experience with distributed systems and microservices architecture, Proven track record building high-throughput backend services, Experience designing scalable and fault-tolerant systems, Ability to implement and optimize APIs 📃 Skills: Python, Azure, ServiceBus, StorageQueues, EventHubs, Microservices, DistributedSystems, APIs, EventDriven, EventSourcing, Streaming, Observability, Monitoring 🏢 Description: Location: Remote Type: Full-time Level: Senior Duration: 4 months Start: ASAP We are looking for an experienced Senior Backend Engineer to join a team responsible for building and scaling a high-throughput, event-driven platform operating at massive scale. Your primary focus will be the event processing backbone — designing, developing, and optimizing services that handle large volumes of messages reliably and efficiently. You will work closely with architects and other senior engineers to implement APIs that expose data and support advanced triage and processing workflows. This role is ideal for someone who enjoys solving hard scalability problems , working with distributed systems, and building resilient backend services that operate under real-world load. Responsibilities Design and build backend services responsible for large-scale event processing Optimize and scale message-based systems to handle high throughput and reliability requirements Implement APIs defined by system architects to expose data and collect processing results Collaborate with cross-functional teams to improve platform performance and resilience Contribute to architectural decisions around scalability, fault tolerance, and observability Core Skills Strong experience with Python as a primary backend language Deep expertise in scaling message queue systems (e.g. Azure Service Bus, Storage Queues, Event Hubs or similar) Solid understanding of microservices architecture and distributed systems Proven experience building high-throughput, resilient backend services Strong problem-solving skills and ability to work with complex systems Highly Desirable Experience with event-driven or event sourcing architectures Background in data processing frameworks or streaming systems Experience building platforms related to observability, monitoring, or large-scale event management Familiarity with designing systems for fault tolerance and graceful degradation What we offer Work on technically challenging systems operating at very large scale High level of autonomy and real influence on system architecture Collaboration with experienced engineers in a mature engineering environment Competitive compensation and flexible working model Project with strong technical ownership

🏢 Summary: Senior Test Automation Engineer role focused on backend/API automation (70%) and web/mobile frontend testing (30%), with responsibility for designing scalable test frameworks and embedding quality gates in CI/CD pipelines. The position involves performance testing, integration and E2E validation, and close collaboration with development teams. The engineer will also lead code reviews, mentor others, and drive best practices across the SDLC. 🗂️ Requirements: 5+ years of commercial experience in test automation, Proficiency in Java and/or JavaScript, Strong knowledge of OOP, SOLID and clean code principles, Advanced Git workflow and code review experience, Expertise in REST Assured and Postman, Experience with Selenium or Selenide, Cypress, TestNG, JUnit, Cucumber, Experience with Appium and XCUITest, Experience integrating automated tests into CI/CD pipelines, Hands-on experience with Gatling, Comprehensive understanding of SDLC, English proficiency at B2/C1 level, Availability for hybrid work with regular on-site presence in Warsaw 📃 Skills: Java, JavaScript, REST, RESTAssured, Postman, Selenium, Selenide, Cypress, TestNG, JUnit, Cucumber, Appium, XCUITest, Gatling, JMeter, Git, CI/CD, Jira, Xray, JSON, OOP, SOLID, KISS 🏢 Description: co.brick talents — powered by AI, powered by people. We are seeking a technically mature Senior Test Automation Engineer to drive the quality assurance lifecycle, focusing heavily on backend/API validation (70%) while maintaining robust web and mobile frontend coverage (30%). In this role, you will go beyond executing standard test plans—you will architect and maintain scalable automated testing frameworks, integrate new performance or tooling proof-of-concepts, and actively mentor mid-level engineers. You will collaborate closely with cross-functional development squads to identify critical system paths, introduce stable quality gates, and champion software engineering best practices. Details Seniority: Senior (5+ years of commercial experience). Allocation: Full-time (1 FTE). Rate: Up to 120 PLN/h. Start Date: ASAP. Languages: English at a B2/C1 level (clear, effective communication across teams). Work Model & Location: Hybrid. Required on-site presence at the client's office in Warsaw, Poland for 1 day every two weeks (specifically Thursdays) , plus an additional 2–3 days on-site every 2–3 months for strategic planning sessions. Responsibilities Test Architecture & Strategy: Plan, design, and execute integration, system, usability, and End-to-End (E2E) testing suites. Support business units during User Acceptance Testing (UAT) phases. Backend & API Automation ($70\%$ Focus): Build and scale automated API test coverage, verifying data contracts, JSON payloads, and response structures. Frontend & Mobile Automation ($30\%$ Focus): Maintain and extend cross-browser web automation and native mobile testing workflows. CI/CD & Pipeline Quality Gates: Embed automated tests seamlessly into distribution pipelines, ensuring high availability, continuous validation, and rapid feedback loops. Performance Testing: Conduct load, stress, and scalability profiling to identify system bottlenecks. Leadership & Code Quality: Lead technical code reviews, promote engineering design patterns, run exploratory PoCs for fresh technologies, and mentor team members to foster a proactive engineering culture. Requirements Core Development Baseline Proficiency in Java and/or JavaScript (JS) . Strong understanding of clean code principles, OOP, SOLID , and KISS . Advanced Git workflow mastery and experience handling code reviews. API Testing & Automation Expert knowledge of REST Assured and Postman . Deep understanding of API response schemas and integration contract validation. Automation Frameworks & Ecosystem Web Front: Selenium / Selenide (primary web standard), Cypress , TestNG , JUnit , and Cucumber . Mobile: Appium and XCUITest . Test Management: Jira (highly preferred with Xray integration). Comprehensive expertise spanning the entire Software Development Life Cycle (SDLC). Performance & Pipelines Gatling (the primary performance testing tool within the organization). Expert control over CI/CD process chains and runner integration. Nice to have: JMeter . Soft Skills & Core Competencies Strong mentorship attitude with a natural drive to support and upscale peer engineers. Proactive mindset with excellent planning, prioritization, and analytical skills. High adaptability—comfortable managing context-switching in a dynamic environment.

🏢 Summary: Senior QA Engineer role focused on end-to-end testing of integration systems and data platforms built on event-driven architecture (Kafka) within global supply chain processes. The position involves data validation, analysis of complex integrations, and gradual ownership of test automation in an international Agile environment. Remote-first collaboration with cross-functional teams. 🗂️ Requirements: Several years of experience as Senior QA Engineer, Experience in testing event-driven systems, Practical experience with Kafka, Experience with data platforms, data pipelines or integration systems, Knowledge of component, integration, system and E2E testing methodologies, Experience working in Agile/Scrum, Proficiency with JIRA, Proficiency with TestRail or Xray, Strong analytical skills in data validation and mapping analysis 📃 Skills: Kafka, JIRA, TestRail, Xray, Java, Agile, Scrum, E2E, SQL 🏢 Description: Nasz Klient to międzynarodowa organizacja rozwijająca nowoczesne rozwiązania technologiczne dla branży logistycznej i łańcucha dostaw. Projekt koncentruje się na rozwoju i testowaniu platform danych oraz systemów opartych o architekturę zdarzeniową (event-driven), wspierających globalne procesy spedycyjne. Szukamy doświadczonej osoby na stanowisko Senior QA Engineer , która nie tylko zadba o jakość testów, ale również będzie aktywnie analizować dane, procesy biznesowe i zależności między systemami. TRYB PRACY: 100% zdalnie (1 x w miesiącu przyjazdy do biura w Warszawie) CZYM BĘDZIESZ SIĘ ZAJMOWAĆ? Prowadzeniem kompleksowych działań testowych end-to-end dla systemów integracyjnych oraz platform danych, obejmujących przepływy biznesowe i techniczne Projektowaniem, rozwijaniem i utrzymywaniem scenariuszy testowych dla architektury event-driven (w szczególności systemów opartych o Kafka Analizą i walidacją mapowań danych, transformacji oraz jakości danych w złożonych środowiskach integracyjnych Diagnozowaniem defektów poprzez analizę przepływów integracyjnych, logiki mapowań oraz zachowania komponentów systemu Współpracą z zespołami developerskimi, ekspertami domenowymi i biznesem w środowisku międzynarodowym Wspieraniem oraz stopniowym przejmowaniem inicjatywy w obszarze automatyzacji testów CZEGO OD CIEBIE OCZEKUJEMY? Minimum kilkuletnie doświadczenie jako tester/ka (Senior) , w tym prowadzenie lub koordynowanie działań testowych Doświadczenie w branży supply chain/logistyki (mile widziane systemy freight forwarding ) Praktyczna znajomość testowania systemów event-driven, w szczególności Kafka Doświadczenie z platformami danych , pipeline’ami lub systemami integracyjnymi Znajomość metodologii testowania (komponentowe, integracyjne, systemowe, E2E) Praca w środowisku Agile/Scrum oraz dobra znajomość narzędzi takich jak JIRA oraz TestRail/Xray Bardzo dobre umiejętności analityczne oraz komunikacyjne Nice to have: Doświadczenie lub chęć rozwoju w automatyzacji testów (np. Java ) Znajomość lub ekspozycja na customowe frameworki testowe Doświadczenie w walidacji dużych transformacji danych i specyfikacji mapowań DLACZEGO WARTO? Długoterminowa współpraca w modelu B2B – kontrakt na min. 12 miesięcy z możliwością przedłużenia Realny wpływ na jakość i rozwój globalnych systemów data & supply chain Możliwość pracy w międzynarodowym środowisku oraz współpracy z ekspertami domenowymi Elastyczny model pracy (głównie zdalnie + sporadyczne wizyty w biurze) Kierunek rozwoju w stronę automatyzacji testów (docelowo większy udział automatyzacji w projekcie) Dziękujemy za wszystkie zgłoszenia! Skontaktujemy się z wybranymi osobami.

🏢 Summary: Senior QA Automation Engineer role focused on backend and frontend test automation, integration and performance testing, and improving QA frameworks and processes. The position involves close collaboration with development teams, mentoring others, and driving testing standards in a hybrid work model. 🗂️ Requirements: 5+ years of QA/Automation experience, Strong programming skills in Java and/or JavaScript, Experience with Jira and Xray, Experience with Git, Experience with Postman for API testing, Understanding of CI/CD pipelines and tools, Knowledge of SDLC, Understanding of API structures and responses, Experience in performance testing, Experience building and maintaining testing frameworks, Experience with code reviews, Knowledge of SOLID, KISS, and OOP principles, Strong communication skills, Analytical thinking, Ability to work in a dynamic environment 📃 Skills: Java, JavaScript, Jira, Xray, Git, Postman, CI/CD, SDLC, Selenium, Selenide, Cypress, TestNG, JUnit, Cucumber, JMeter, REST, Assured, Gatling, Appium, XCUI, SOLID, KISS, OOP 🏢 Description: About the Role We are looking for a Senior QA Automation Engineer with a strong technical background in both frontend and backend testing (approx. 30% Frontend / 70% Backend). This role is ideal for a technically mature professional who can independently deliver high-quality solutions while also mentoring others and driving best practices across teams. Key Responsibilities Plan and execute integration, system, and usability testing Participate in End-to-End (E2E) and User Acceptance Testing (UAT) Collaborate with developers to understand critical paths and ensure product stability Strengthen cooperation and communication across Dev Teams Contribute to improving QA processes, frameworks, and testing standards Requirements 5+ years of experience in QA/Automation Strong programming skills in Java and/or JavaScript Practical experience with: Jira (preferably with Xray) Git Postman for API testing Deep understanding of: CI/CD pipelines and tools Software Development Life Cycle (SDLC) API structures and responses Experience in: Performance testing Building and maintaining testing frameworks Code reviews Tool integration and adoption of new technologies (PoC, showcases) Solid knowledge of: Design patterns and programming principles (SOLID, KISS, OOP) Automation & Testing Stack Web Testing Selenium / Selenide (primary tools) Cypress (depending on the team) TestNG / JUnit Cucumber JMeter (nice to have) API Testing REST Assured TestNG / JUnit Gatling (nice to have) Mobile Testing Appium XCUI Test (if applicable) Performance Testing Gatling (preferred) JMeter (nice to have) Soft Skills Strong communication skills Excellent analytical thinking Mentorship and knowledge-sharing mindset Proactive attitude and ownership Strong planning and prioritization skills Ability to work in a dynamic environment (context switching) Passion for driving technical innovation Work Model Hybrid model: 1 day every two weeks (Thursday) in the Warsaw office Additional on-site presence (2–3 days) every 2–3 months for planning sessions

🏢 Summary: Senior Backend Engineer role focused on designing and developing scalable, reliable backend services using Java. The position involves working in a cross-functional team to build high-performance systems, improve architecture, and support CI/CD and production environments. 🗂️ Requirements: 5+ years Backend Engineering experience, Strong Java proficiency, Solid knowledge of databases and SQL, Experience with RESTful APIs, Experience with microservices architecture, Experience with high-load systems, Experience with Docker and Kubernetes, Experience with AWS or GCP, Knowledge of CI/CD pipelines, Understanding of Agile practices 📃 Skills: Java, SQL, REST, Microservices, Docker, Kubernetes, AWS, GCP, CI/CD, Golang, Python 🏢 Description: We are looking for a Senior Backend Engineer with strong Java experience to help us design and develop scalable solutions. You will work in a cross-functional team, building reliable services and contributing to the continuous improvement of our systems. This role is ideal for someone who enjoys solving complex problems and driving technical excellence. 💼 Responsibilities: Design, develop, and maintain backend features and services. Collaborate with teams to define requirements and integrate systems. Ensure performance, scalability, and reliability of applications. Contribute to CI/CD processes and support production systems. Write clear documentation and share knowledge within the team. ✅ Requirements: 5+ years of experience as a Backend Engineer, with strong Java skills (Golang/Python is a plus). Solid understanding of databases and SQL. Experience with RESTful API design, microservices, and high-load systems. Familiarity with Docker, Kubernetes, and cloud environments (AWS/GCP). Knowledge of CI/CD pipelines and Agile practices. Strong problem-solving and communication skills. 🎁 We offer: Stable employment in a fast-growing company. Flexible and remote-friendly working model. Health and wellbeing benefits. Learning and development opportunities. Modern equipment and comfortable work environment.

🏢 Summary: Senior/Staff Backend Engineer role focused on building and evolving a large-scale, event-driven platform using Java, Kafka Streams, and AWS. The position involves hands-on work with high-volume data flows, real-time stream processing, distributed systems, and production reliability. You will take strong technical ownership in a small team, shaping architecture, standards, and production readiness. 🗂️ Requirements: 7+ years of backend engineering experience, Strong hands-on experience with Java, Strong hands-on experience with Spring Boot, Deep production experience with Kafka Streams (topologies, joins, aggregations, windowing, state stores), Experience with event-driven or distributed systems, Hands-on experience with AWS services, Experience with Kubernetes and containerized deployments, Experience with PostgreSQL, MongoDB, and Redis, Strong knowledge of monitoring, debugging, and performance optimization, Ability to work independently in evolving technical environments, Professional English communication skills 📃 Skills: Java, Spring, Kafka, KafkaStreams, AWS, EKS, S3, SQS, SNS, Kinesis, Lambda, Kubernetes, PostgreSQL, MongoDB, Redis, Terraform, Helm, Prometheus, Grafana, Micrometer, Kotlin 🏢 Description: Senior / Staff Backend Engineer (Java, Kafka Streams, AWS) Location: Kraków, hybrid Contract: B2B or UoP B2B budget: up to 210 PLN/h + VAT Work model: around 3 days per week from the office We are looking for a Senior or Staff Backend Engineer to join a small, high-impact engineering team building a large-scale, event-driven platform. This is a hands-on role for someone who enjoys working close to real production systems: high-volume data flows, asynchronous processing, external integrations, reliability, observability and technical ownership. You will join a team where the codebase and domain are evolving, so this is a good opportunity for an engineer who does not need every problem to be fully defined before getting started. You will be expected to investigate, create structure, improve standards and make pragmatic technical decisions. What you will do Build and evolve backend services using Java and Spring Boot Design and maintain real-time event-processing flows using Kafka Streams Work with stream-processing concepts such as topologies, transformations, joins, aggregations, stateful processing and data routing Integrate external systems and infrastructure into a scalable internal platform Improve reliability, observability and production readiness of services handling high-volume data Investigate production issues, performance bottlenecks and data-flow problems Work with AWS, Kubernetes, PostgreSQL, MongoDB, Redis, Terraform and Helm Contribute to code reviews, architecture decisions, documentation and engineering standards Collaborate with product, platform and engineering stakeholders across an international environment What we are looking for 7+ years of backend engineering experience Strong, current hands-on experience with Java and Spring Boot Deep practical experience with Kafka Streams in production This should go beyond Kafka producers/consumers and include work with stream-processing logic, joins, aggregations, windowing, state stores or topology design Background in event-driven, distributed or real-time systems Hands-on AWS experience, ideally with services such as EKS, S3, SQS, SNS, Kinesis or Lambda Experience with Kubernetes , containers and production deployment environments Good understanding of databases such as PostgreSQL, MongoDB and Redis Strong production mindset: monitoring, debugging, reliability, performance and incident investigation Ability to work independently in an evolving and not always fully documented technical environment Clear English communication skills and confidence explaining technical topics to both engineers and non-technical stakeholders Nice to have Kotlin experience Experience with high-throughput data processing or streaming platforms Terraform, Helm, Prometheus, Grafana, Micrometer or similar observability tooling Experience in a small product team, scale-up or ownership-heavy engineering environment Familiarity with AI-assisted development tools What you can expect A technically challenging role focused on real production systems rather than isolated feature delivery Strong ownership Small team setup with room to influence architecture, standards and ways of working International engineering environment Clear recruitment process focused on practical engineering discussions Recruitment process Introductory conversation with the Hiring Manager Technical interview focused on Kafka/use cases and Java/code quality Final discussion with senior technical leadership The full company and product context will be shared during the first recruiter call.