Senior .NET Developer, Tickets Selling System

🏢 Summary: Senior .NET Backend Developer role focused on modernizing and expanding a complex international ticket sales platform built on microservices architecture and hosted on AWS. The position involves developing and maintaining scalable backend services, refactoring existing systems, and collaborating with cross-functional teams. The project uses the latest .NET technologies and supports integration with multiple external systems including GDS APIs. 🗂️ Requirements: 7+ years of backend development experience, 7+ years of commercial development experience on .NET platform, Strong proficiency in C# and .NET, Experience with RESTful WebAPI, Experience working with microservices architecture, Experience with unit testing frameworks (e.g., nUnit), Experience with mocking frameworks (e.g., Moq), Experience with dependency injection (e.g., Autofac), Experience with Entity Framework or NHibernate, Experience with DBMS systems, Understanding of Clean Code and OOP principles, Understanding of SOLID principles, Understanding of Agile methodology, Good spoken English 📃 Skills: .NET, C#, REST, WebAPI, Microservices, MSSQL, PostgreSQL, DynamoDB, AWS, nUnit, Moq, Autofac, EntityFramework, NHibernate, OOP, SOLID, Agile, JWT, OAuth2, OpenID 🏢 Description: Client The company is one of the regional leaders in the industry and is currently launching their new product, an international platform for ticket sales. The company's annual income exceeds 100 million euros. Join a great company, not merely an individual project Project overview The client uses various tools to reach their customers, such as a mobile app, a responsive web application, or communicating with them directly through the call center. The system is very complex, it must comply with a large number of regulations. We provide APIs for different clients including the biggest Global Distribution Systems (GDSes). Our client is committed to ensuring that the system will be as modern as possible. It is based on microservice architecture with the use of continuous integration, where a few hundred components operate independently of each other and can be used as they become available. This increases the modularity of the system and optimizes the use of the services. All components run on AWS. Team Several independent teams are working on the project. The goals of each team are limited to the part of the system they're working on. DataArt's specialists are working on the back-end in one of the teams. Position overview DataArt is currently helping to modernize and develop the IT system of an independent online retailer of railroad tickets. Technology stack .NET (always working with newest versions) microservices REST API MSSQL migrating to Postgres, DynamoDB Responsibilities Refactoring and expanding tickets selling system Develop, enhance, and maintain high-quality, scalable code Work collaboratively with cross-functional teams to support the implementation of new features and achieve their objectives Requirements 7+ years of backend development experience 7+ years of experience in commercial software development on the .NET platform Understanding of and experience working with C# Development experience with .NET Strong skills in Clean Code and OOP Knowledge of WebAPI Understanding of microservices architecture Experience with unit testing (like nUnit) and mocking frameworks (preferred Moq) Experience with dependency injection (preferred Autofac) Knowledge of Entity Framework or NHibernate Experience working with any DBMS system Understanding of SOLID principles Understanding of Agile development methodology Good spoken English Nice to have Knowledge of basic Authentication: types of Authentication, JWT, OAuth 2.0, OpenId Connect What We Offer: Vacation days : Up to 26 business days per year. 10 illness/special days off per year (fully paid, no medical papers needed) for all contract types Health and life insurance (Luxmed) MyBenefit platform with Multisport option Internal psychological support service English language classes from the first working day Access to external learning platforms : O’Reilly, LinkedIn Learning, Udemy, and a wide catalog of diverse internal training Flexible workplace : work from the office, from home, or choose a hybrid option Tech Skills Mentoring Program Opportunities to develop as a public speaker, mentor, or technical interviewer Fully paid idle (bench) when not involved in a project Certification reimbursement (AWS, GCP, Microsoft, etc.)

🏢 Summary: Backend .NET Developer role focused on modernizing and expanding a large-scale international ticket sales platform built on microservices and deployed on AWS. The position involves developing and refactoring a complex, regulation-compliant system that integrates with external clients via REST APIs. You will work on scalable backend services within a distributed architecture supporting web and mobile applications. 🗂️ Requirements: 7+ years backend development experience, 7+ years commercial .NET development, Strong C# knowledge, Experience with .NET WebAPI, Experience with microservices architecture, Experience with unit testing frameworks, Experience with dependency injection, Experience with ORM frameworks, Experience with relational or NoSQL databases, Knowledge of Clean Code, OOP, SOLID, Experience in Agile environment 📃 Skills: .NET, C#, WebAPI, REST, Microservices, MSSQL, PostgreSQL, DynamoDB, AWS, nUnit, Moq, Autofac, EntityFramework, NHibernate, OOP, SOLID, JWT, OAuth2, OpenIdConnect, Agile 🏢 Description: Client The company is one of the regional leaders in the industry and is currently launching their new product, an international platform for ticket sales. The company's annual income exceeds 100 million euros. Project overview The client uses various tools to reach their customers, such as a mobile app, a responsive web application, or communicating with them directly through the call center. The system is very complex, it must comply with a large number of regulations. We provide APIs for different clients including the biggest Global Distribution Systems (GDSes). Our client is committed to ensuring that the system will be as modern as possible. It is based on microservice architecture with the use of continuous integration, where a few hundred components operate independently of each other and can be used as they become available. This increases the modularity of the system and optimizes the use of the services. All components run on AWS. Team Several independent teams are working on the project. The goals of each team are limited to the part of the system they're working on. DataArt's specialists are working on the back-end in one of the teams. Position overview DataArt is currently helping to modernize and develop the IT system of an independent online retailer of railroad tickets. Technology stack .NET (always working with newest versions) microservices REST API MSSQL migrating to Postgres, DynamoDB Responsibilities Refactoring and expanding tickets selling system Develop, enhance, and maintain high-quality, scalable code Work collaboratively with cross-functional teams to support the implementation of new features and achieve their objectives Requirements 7+ years of backend development experience 7+ years of experience in commercial software development on the .NET platform Understanding of and experience working with C# Development experience with .NET Strong skills in Clean Code and OOP Knowledge of WebAPI Understanding of microservices architecture Experience with unit testing (like nUnit) and mocking frameworks (preferred Moq) Experience with dependency injection (preferred Autofac) Knowledge of Entity Framework or NHibernate Experience working with any DBMS system Understanding of SOLID principles Understanding of Agile development methodology Good spoken English Nice to have Knowledge of basic Authentication: types of Authentication, JWT, OAuth 2.0, OpenId Connect What We Offer: Vacation days : Up to 26 business days per year. 10 illness/special days off per year (fully paid, no medical papers needed) for all contract types Health and life insurance (Luxmed) MyBenefit platform with Multisport option Internal psychological support service English language classes from the first working day Access to external learning platforms : O’Reilly, LinkedIn Learning, Udemy, and a wide catalog of diverse internal training Flexible workplace : work from the office, from home, or choose a hybrid option Tech Skills Mentoring Program Opportunities to develop as a public speaker, mentor, or technical interviewer Fully paid idle (bench) when not involved in a project Certification reimbursement (AWS, GCP, Microsoft, etc.)

🏢 Summary: Development role focused on building and modernizing a large-scale, microservice-based ticket sales platform running on AWS. The position involves backend development in .NET 7/8, creating new features and refactoring existing components within an Agile environment. It offers strong engineering practices, continuous integration, and collaboration within multiple backend squads. 🗂️ Requirements: 3–5 years of backend development experience, 3–5 years of commercial development on .NET platform, Strong knowledge of C#, Practical experience with AWS, Understanding of Clean Code and OOP, Knowledge of SOLID principles, Experience with WebAPI, Understanding of microservices architecture, Experience with unit testing (e.g., nUnit), Experience with mocking frameworks (e.g., Moq), Experience with dependency injection (e.g., Autofac), Knowledge of Entity Framework or NHibernate, Experience with DBMS systems, Understanding of Agile methodology, Good spoken English 📃 Skills: .NET, C#, AWS, REST, WebAPI, Microservices, nUnit, Moq, Autofac, EntityFramework, NHibernate, Postgres, DynamoDB, MSSQL, RDS, CI 🏢 Description: Client Our client is one of the regional leaders in the industry and is currently launching a new product—an international platform for ticket sales. The company’s annual revenue exceeds €100 million. Join a great company, not merely an individual project Project overview The client uses various tools to reach their customers, such as a mobile app, a responsive web application, or communicating with them directly through the call center. The system is big and modular (microservice-based), complying with a number of regulations. We provide APIs for different clients including the biggest Global Distribution Systems (GDSes). We also provide solutions that are labeled by more than half of Train Operating Companies (TOCs) in the UK. Our client is committed to ensuring that the system will be as modern as possible. It is based on a microservice architecture with the use of continuous integration, where a few hundred components operate independently of each other and can be used as they become available. This increases the modularity of the system and optimizes the use of the services. All components run on AWS. The backend also includes .NET 7/8, and REST API is actively modernized to Cloud Native solutions (RDS like Postgres, DynamoDB) from MSSQL. The client has a policy to work with the latest technology, and they move to newer versions when they are available. Team Several independent teams are working on the project. The goals of each team are limited to the part of the system they're working on. DataArt's specialists are working on the backend in several teams. The project has a team of 30+ .NET developers who work on the backend, divided into smaller squads. Position overview DataArt is currently helping develop new features and modernize the IT system of an independent online railroad ticket retailer. The project is a great place to work and grow for Middle engineers due to strong engineering practices (microservices, clean code, extensive unit testing, CI, dozens of production deployments weekly, the Scout Rule, code reviews, and an Agile approach), continuous technical refactoring, and a senior team that is willing to learn and share experience. Responsibilities Development of new features, expanding the ticket-selling system + refactoring 80-90% backend development 20-10% team meetings Requirements From 3 to 5 years of backend development experience From 3 to 5 years of experience in commercial software development on the .NET platform Understanding of and experience working with C# Good understanding of Cloud - AWS practical experience mandatory Strong skills in Clean Code and OOP Understanding of SOLID principles Knowledge of WebAPI Understanding of microservices architecture Experience with unit testing (like nUnit) and mocking frameworks (preferred Moq) Experience with dependency injection (preferred Autofac) Knowledge of Entity Framework or NHibernate Experience working with any DBMS system Understanding of Agile development methodology Good spoken English What We Offer: Vacation days : Up to 26 business days per year. 10 illness/special days off per year (fully paid, no medical papers needed) for all contract types Health and life insurance (Luxmed) MyBenefit platform with Multisport option Internal psychological support service English language classes from the first working day Access to external learning platforms : O’Reilly, LinkedIn Learning, Udemy, and a wide catalog of diverse internal training Flexible workplace : work from the office, from home, or choose a hybrid option Tech Skills Mentoring Program Opportunities to develop as a public speaker, mentor, or technical interviewer Fully paid idle (bench) when not involved in a project Certification reimbursement (AWS, GCP, Microsoft, etc.)

🏢 Summary: Senior iOS Engineer role focused on modernizing and expanding a large-scale international ticket sales platform built on microservices and AWS. The position centers on developing and optimizing a mobile app through data-driven experimentation, A/B testing, and feature flag management. You will collaborate with cross-functional teams to deliver scalable, high-quality iOS solutions using modern Apple technologies. 🗂️ Requirements: 6+ years of iOS development experience with Swift, Hands-on experience with experimentation and R&D initiatives, Experience with Statsig or similar experimentation platforms, Strong knowledge of Clean Code and OOP principles, Proficiency in SwiftUI and UIKit, Experience with unit testing and working without dedicated QA engineers, Understanding of SOLID principles, Familiarity with Agile methodology, Good spoken English 📃 Skills: Swift, SwiftUI, UIKit, GCD, CoreData, SPM, TestFlight, Figma, Statsig, CUPED, Bayesian, AWS, Microservices, UnitTesting, UITesting, ABTesting, OOP, SOLID, Agile 🏢 Description: Client Our client is a regional leader in the transportation industry, with annual revenue exceeding €100 million, currently launching a new international ticket sales platform. Project overview The client engages users through a mobile app, responsive web application, and call center. The system is complex and must comply with numerous regulations. The system is built on a microservice architecture with continuous integration. Hundreds of components run independently on AWS, increasing modularity and optimizing service usage. Team Multiple independent teams contribute to different parts of the system. DataArt specialists are embedded across these teams. The mobile team is focused on shaping the future of the client’s mobile app—enhancing performance and evolving its functionality. Position overview DataArt is supporting the modernization and development of the IT system for an independent online railway ticket retailer. We hire for the company, not just the project, ensuring ongoing opportunities or paid idle time between assignments. In this role, you will enhance digital products through data-driven experimentation and analytics. Responsibilities include running large-scale A/B and multivariate tests using tools like Statsig, applying advanced statistical methods such as CUPED and Bayesian Autotune, automating traffic allocation to optimize feature performance, managing feature flagging with gradual rollouts, kill switches, and targeting, and linking feature flags directly to product metrics. Technology stack iOS: Swift UI: SwiftUI, UIKit Concurrency: GCD, Swift Concurrency Persistence: CoreData Tooling: SPM, TestFlight, Figma Testing: Unit Testing, UI Testing, A/B Testing Responsibilities Refactor and expand the ticket-selling system Develop, enhance, and maintain high-quality, scalable code Collaborate with cross-functional teams to implement new features and support experimentation initiatives Requirements 6+ years of iOS development experience using Swift Experience in experimentation and R&D Hands-on experience with Statsig or similar platforms Strong Clean Code and OOP skills Knowledge of SwiftUI and UIKit Experience with unit testing and working without dedicated QA engineers Understanding of SOLID principles Familiarity with Agile development methodology Good spoken English

🏢 Summary: The offer is for a Test Automation Engineer responsible for designing, implementing, and supporting automated testing frameworks for internal and client-facing systems. The role involves close collaboration with architecture, DevOps, and product teams to build robust API and UI automation solutions in Agile environments. The position requires strong experience in automation tools, programming, and QA process setup. 🗂️ Requirements: 3+ years of experience in Test Automation, Experience in two programming languages, Experience with at least two automation tools, Experience in API and UI automation, Familiarity with Git or Bitbucket, Understanding of RESTful web services, Knowledge of automated testing principles and practices, Ability to set up QA process from scratch, Experience working in Agile (Scrum or Kanban), Spoken English 📃 Skills: Java, JavaScript, C#, Python, Playwright, Selenide, Selenium, Cypress, API, UI, Git, Bitbucket, REST, Scrum, Kanban 🏢 Description: Position overview DataArt is a global software engineering firm and a trusted technology partner for market leaders and visionaries. Our world-class team designs and engineers data-driven, cloud-native solutions to deliver immediate and enduring business value. We promote a culture of radical respect, prioritizing your personal well-being as much as your expertise. We stand firmly against prejudice and inequality, valuing each of our employees equally. We respect the autonomy of others before all else, offering remote, onsite, and hybrid work options. Our Learning and development centers, R&D labs, and mentorship programs encourage professional growth. Our long-term approach to collaboration with clients and colleagues alike focuses on building partnerships that extend beyond one-off projects. We provide the ability to switch between projects and technology stacks, creating opportunities for exploration through our learning and networking systems to advance your career. Responsibilities Implement and support test automation for internal and client facing systems Collaborate with Architecture, InfoSec and DevOps teams to design test automation frameworks for these systems Collaborate with business analysts, developers and product owners to develop comprehensive test automation Build reusable test frameworks Analyze requirements and user stories to build robust automated solutions Follow best coding practices Requirements 3+ years of experience in Test Automation Automation experience in two programming languages (e.g. Java, JavaScript, C#, Python) Experience with at least two Automation Tools (e.g. Playwright, Selenide, Selenium, Cypress etc.) Experience in both: API and UI Automation Familiarity with version control systems such as Git and Bitbucket Solid understanding of RESTful web services. Understanding of automated testing principles and practices Ability and knowledge of how to set up the QAA process from scratch Familiarity with Agile methodologies (Kanban, Scrum) and experience working in Agile teams Spoken English

🏢 Summary: B2B role to design and build high-scale infrastructure and platform solutions in .NET 8 for a global travel-tech product used by millions of users. The position focuses on developing a new architecture and delivering end-to-end solutions for internet-scale systems in a fast-paced environment. 🗂️ Requirements: 5+ years of commercial experience with .NET Core and C#, Strong foundation in computer science, Proficiency in object-oriented design, Knowledge of design patterns, Knowledge of algorithms and data structures, Experience designing end-to-end internet-scale solutions, Experience with large-scale production environments, Good understanding of SQL Server, Good understanding of Redis, Fluent English (written and verbal) 📃 Skills: .NET, C#, SQL, SQLServer, Redis, OOP, DesignPatterns, Algorithms, DataStructures 🏢 Description: Join the client's team in the travel-tech industry. RESPONSIBILITIES In this role, the infrastructure and platform used daily by millions of travelers worldwide will be designed and built. The focus is on full transparency, continuous improvement, innovation, and maximizing the use of technology. The team will be responsible for designing and developing a new architecture in .NET 8 to support high-scale products. REQUIREMENTS A solid foundation in computer science and strong competencies in object-orienteddesign, design patterns, algorithms, and data structures, with solid developmentexperience in .NET Core / C# - At least 5+ years experience. Thrive in a fast-paced environment, able to adapt and learn new technologies quickly. Hands-on experience designing, developing, and deploying end-to-end solutions for internet-scale problems. Good understanding of SQL Server and Redis. Experience with large-scale production environments. Excellent communication skills, initiative, and teamwork. High level of communication skills (written and verbal) in English NICE TO HAVE Experience in travel tech. Working with CI/CD is an advantage. Experience with containers and Kubernetes. Experience with NoSQL databases (like Elasticsearch) WHAT DO WE OFFER ON THIS PROJECT? Cooperation based on a B2B contract. Hybrid work from Warsaw (2 times a week in the office). The support of a dedicated mentor. In the relationship, we focus on direct communication. When you join speedapp, you will be put in touch with a dedicated mentor who will make sure that you enjoy working with us and with the client. Events and integration meetings, as well as participation in various initiatives, e.g., sports. Access to the benefits offering (medical care, life insurance, Multisport card). WHAT DOES THE RECRUITMENT PROCESS LOOK LIKE? Application: Apply and submit your CV. After the application review, the recruiter will contact selected candidates by phone. Screening: Have a conversation with a speedapp recruiter about your experience. Next steps: The speedapp recruiter will explain the recruitment process for the specific position. The speedapp recruiter will stay in touch with you throughout the entire process. ABOUT SPEEDAPP At speedapp, we believe that an organization is only as good as the people who make it up. We are a team of IT experts and other professionals working for our clients around the world (including Israel, Austria, USA). We go far beyond the HR category. We build IT teams and also help manage them. 👉 10 years of experience 👉 +100 clients worldwide +300 hires per year 💎 We have won the prestigious "Forbes Diamonds" award four times (2022, 2023, 2024, 2025). We are a member of the European Fast Growth Icons network and FinTech Poland. We are ranked 18th among the 100 fastest growing companies 2023 by Clutch. DO YOU HAVE ANY QUESTIONS? Contact the recruiter responsible for this process directly. Aleksandra Mazur Senior IT Research Consultant aleksandra.mazur@speedapp.pl +48 728 360 029

🏢 Summary: The role involves designing and building high-scale infrastructure and platform solutions in .NET 8 for a global travel-tech product used by millions of users. The position focuses on developing a new architecture for internet-scale systems with an emphasis on innovation and continuous improvement. It includes end-to-end solution design and deployment in large-scale production environments. 🗂️ Requirements: 5+ years of experience with .NET Core and C#, Strong foundation in computer science, Strong knowledge of object-oriented design, Knowledge of design patterns, Knowledge of algorithms and data structures, Experience designing end-to-end solutions for internet-scale systems, Experience with large-scale production environments, Good understanding of SQL Server, Good understanding of Redis, Fluent English (written and verbal) 📃 Skills: .NET, C#, SQL, SQLServer, Redis, Kubernetes, Docker, Elasticsearch, CI/CD, NoSQL 🏢 Description: Join the client's team in the travel-tech industry.. RESPONSIBILITIES In this role, the infrastructure and platform used daily by millions of travelers worldwide will be designed and built. The focus is on full transparency, continuous improvement, innovation, and maximizing the use of technology. The team will be responsible for designing and developing a new architecture in .NET 8 to support high-scale products. REQUIREMENTS A solid foundation in computer science and strong competencies in object-orienteddesign, design patterns, algorithms, and data structures, with solid developmentexperience in .NET Core / C# - At least 5+ years experience. Thrive in a fast-paced environment, able to adapt and learn new technologies quickly. Hands-on experience designing, developing, and deploying end-to-end solutions for internet-scale problems. Good understanding of SQL Server and Redis. Experience with large-scale production environments. Excellent communication skills, initiative, and teamwork. High level of communication skills (written and verbal) in English NICE TO HAVE Experience in travel tech. Working with CI/CD is an advantage. Experience with containers and Kubernetes. Experience with NoSQL databases (like Elasticsearch) WHAT DO WE OFFER ON THIS PROJECT? Cooperation based on a B2B contract. Hybrid work from Warsaw (2 times a week in the office). The support of a dedicated mentor. In the relationship, we focus on direct communication. When you join speedapp, you will be put in touch with a dedicated mentor who will make sure that you enjoy working with us and with the client. Events and integration meetings, as well as participation in various initiatives, e.g., sports. Access to the benefits offering (medical care, life insurance, Multisport card). WHAT DOES THE RECRUITMENT PROCESS LOOK LIKE? Application: Apply and submit your CV. After the application review, the recruiter will contact selected candidates by phone. Screening: Have a conversation with a speedapp recruiter about your experience. Next steps: The speedapp recruiter will explain the recruitment process for the specific position. The speedapp recruiter will stay in touch with you throughout the entire process. ABOUT SPEEDAPP At speedapp, we believe that an organization is only as good as the people who make it up. We are a team of IT experts and other professionals working for our clients around the world (including Israel, Austria, USA). We go far beyond the HR category. We build IT teams and also help manage them. 👉 10 years of experience 👉 +100 clients worldwide +300 hires per year 💎 We have won the prestigious "Forbes Diamonds" award four times (2022, 2023, 2024, 2025). We are a member of the European Fast Growth Icons network and FinTech Poland. We are ranked 18th among the 100 fastest growing companies 2023 by Clutch. DO YOU HAVE ANY QUESTIONS? Contact the recruiter responsible for this process directly. Aleksandra Mazur Senior IT Research Consultant aleksandra.mazur@speedapp.pl +48 728 360 029

🏢 Summary: Senior .NET Developer / Architect role focused on building and optimizing a cloud-native travel booking platform in a microservices architecture. The position involves designing high-performance flight search and booking flows, integrating with GDS/NDC APIs, and ensuring scalability, reliability, and low-latency performance. The role combines deep technical expertise in distributed systems with strong domain knowledge in airline and travel technology. 🗂️ Requirements: 5+ years experience with C# and .NET, 5+ years experience in travel industry (flight shopping, booking engines, OTA, metasearch), Experience with GDS systems (Sabre, Amadeus, Travelport) and/or NDC APIs, Knowledge of airline concepts (PNR, e-ticketing, fare rules, availability, schedule changes), Experience with cloud-native and distributed architectures, Experience with high-throughput, low-latency systems, Experience with observability tools, Ability to design scalable APIs and asynchronous workflows 📃 Skills: C#, .NET, Azure, AWS, Microservices, REST, SOAP, GDS, NDC, Sabre, Amadeus, Travelport, OpenTelemetry, Grafana, ApplicationInsights, APIs, DistributedSystems, Caching, Concurrency, RateLimiting, CircuitBreakers, AsynchronousProcessing 🏢 Description: In Goelett, we are an extraordinary mix of travel industry experts, product, and software engineers, developing a successful online booking tool for corporations and large organizations. Today, as a part of the sector leader S4BT Group, we support 500k+ business users making thousands of bookings a day. We are seeking a Senior.Net Developer / Architect who is keen on working within a product development team, has a background in system and integration analysis, and is ready to take on a dynamic career opportunity by driving requirements analysis, resolving system issues, and enhancing product functionalities! Work model: hybrid (3 days in the office + 2 days remote / weekly) – office located in Warsaw, PL. What you will be doing: Develop clean, scalable code using C# / .NET in a microservices, cloud-native architecture (Azure/AWS). Design and implement high-performance travel search and booking flows (shopping, pricing, availability, ticketing). Integrate with GDS, NDC, LCC APIs. Work with flight and ancillary services including seat maps, baggage, fare families, upsell/cross-sell. Optimize search performance (latency, caching strategies, concurrency, rate limiting, resiliency patterns). Implement orchestration layers for multi-provider search aggregation and normalization of responses. Handle complex pricing logic (fare rules, combinability, branded fares, dynamic pricing). Monitor and optimize system performance, observability (logging, tracing, metrics), and reliability (SLAs/SLOs). Build and maintain scalable APIs (REST/SOAP), event-driven components, and asynchronous workflows. Ensure high availability and fault tolerance in distributed systems (circuit breakers, retries, fallbacks). What we're looking for: 5+ years of professional experience in software development using C# / .NET and modern cloud architectures. 5+ years of travel experience in travel business: flight shopping, booking engines, OTA platforms, or metasearch. Hands-on experience integrating with GDS (Sabre, Amadeus, Travelport) and/or NDC APIs. Solid understanding of airline concepts: PNR, e-ticketing, fare rules, availability, schedule changes, cancellations. Experience with high-throughput, low-latency systems and distributed architectures. Experience with observability tools (e.g., OpenTelemetry, Application Insights, Grafana). Ability to translate business requirements (conversion, pricing accuracy, availability) into technical solutions. What we offer: A truly global perspective – develop your international mindset by collaborating daily with colleagues from diverse cultures and backgrounds across the world. Real impact – contribute to shaping the future of one of the most user-centric companies in the travel-tech industry. Your ideas and solutions will reach thousands of users globally. Medical care – because your well-being matters. Multisport card – keep your body as active as your mind. Extra days off – celebrate your day with a paid day off for your birthday, and another to give back through volunteering. Language courses – grow your communication skills and connect effortlessly in our multicultural environment. Team integrations & fun events. Lunch vouchers – enjoy your breaks with tasty meals on us.

🏢 Summary: Development role focused on building and maintaining a modern microservices-based payment processing platform in a high-volume environment. The position involves designing, implementing, and supporting Java-based services, ensuring scalability, reliability, and performance. Work is done in a hybrid model with strong emphasis on quality, testing, and production support. 🗂️ Requirements: Minimum 3 years of experience in similar role, Strong Java development experience, Knowledge of Spring Boot, Understanding of microservices architecture, Understanding of distributed systems, Experience with API design, Experience with at least some of the listed technologies, Ability to perform unit testing and code reviews, Fluent English 📃 Skills: Java, Spring, SpringBoot, Microservices, Kubernetes, OpenShift, Kafka, RabbitMQ, MongoDB, Oracle, SQL, REST, Groovy, Maven, Jenkins, Jira, Confluence 🏢 Description: About the Project Our client is a European payments organization undergoing a major digital transformation focused on modernizing its core transaction‑processing platform. The team is building a modern microservices‑based environment designed to increase scalability, reliability, and performance across high‑volume payment operations. Technology stack in use: Java 21 (Spring Boot 3), OpenShift / Kubernetes, Apache Kafka / Rabbit MQ for streaming and queuing, MongoDB, Oracle Database, multiple DevOps tools for development, automation and monitoring. Work mode: hybrid, 3-4 per week from Cracow office Key Responsibilities: ·       Design, develop and support testing payment services features together with the team. ·       Resolve issues by troubleshooting and root cause analysis and support in production issue analysis when needed. ·       Ensure high quality via unit testing and code reviews. ·       Demo and document the results of work in demo sessions. Required Experience & Skills: ·       At least 3 years on similar position ·       Technical knowledge in at least some of the technologies used is needed. ·       Java development skills are the most relevant. ·       Understanding of microservices architecture and distributed systems. ·       Familiarity with API design principles. ·       Fluent English Additional Valuable Skills: ·       Experience in designing and implementing high-throughput, low-latency systems capable of handling large data volumes ·       Groovy, Maven, Jenkins ·       Knowledge of the Card Processing domain ·       Documentation and use of Jira/Confluence ·       Excellent communication and coordination skills We offer Ongoing support from a dedicated agent who is caring about your project continuity, contact with clients, necessary formalities, work comfort, and development. Career Development Program – advice on career planning based on the latest trends and market needs in IT, including consultations with career agents and mentors. Access to 7N Learning & Development – a development and educational platform offering webinars, a library of articles and industry reports, and frequent invitations to both one-time and recurring events focused on technical, business, and lifestyle topics. Spectacular events, both for you (e.g., annual Kick-Off trip , Christmas parties, or Summer Olympics sports events) and for your loved ones (e.g. family picnics), Professional growth Professional growth beyond your current project. You can actively engage in knowledge sharing through the 7N Services offering, designed for 7N clients. Connections and access to the expertise of top IT professionals in the market – the average professional tenure of our consultants in Poland is over 10 years, A complete benefits package, including funding for medical care, life insurance, sports cards for you and your loved ones, as well as discounts in stores in Poland and abroad

🏢 Summary: B2B Tech Lead role to design and deliver a scalable integration framework for AI-powered financial services products. The position focuses on building production-ready, event-driven integrations using Node.js and AWS within a regulated FinTech environment. You will lead architectural decisions and guide the team in implementing resilient, cloud-native microservices solutions. 🗂️ Requirements: 10+ years of experience in software development, Strong commercial experience with Node.js, Strong experience with AWS and cloud-native architecture, Excellent knowledge of event-driven architecture, Experience designing and building microservices systems, Experience building integrations with external APIs and third-party systems, Experience with high-volume data processing systems, Practical knowledge of API quotas, rate limits, retries, and resilience patterns, Experience operating production-grade systems, Technical leadership experience in integration or platform teams, Fluency in Polish, Advanced English proficiency 📃 Skills: Node.js, AWS, Microservices, Event-driven, APIs, Cloud, Integration, FinTech, AI, LLM 🏢 Description: Contract: B2B Rate: 150 - 180 PLN/h net + VAT Location: Remote within Poland Project: Building an integration framework for AI-powered products in the financial services sector Start: 15 June 2026 Key Technologies/Areas Backend: Node.js Cloud: AWS Architecture: Microservices, event-driven architecture, integration frameworks Data: High-volume data processing, external API integrations, rate limits, quotas Engineering: Technical leadership, architecture, stakeholder communication, scalable production systems Domain: FinTech, regulated financial services, compliance, AI-powered products Project Overview Join our team as an Tech Lead and support a FinTech company building AI-powered products for the financial services sector. The project focuses on developing an Integration Framework that enables new customers to easily connect with advanced AI systems used for adviser support, compliance monitoring, quality assurance, and customer interaction analysis. This is a hands-on technical leadership role focused on designing and delivering the integration framework, setting integration patterns, and guiding the engineering team on event-driven, scalable, and resilient architecture. You will lead the technical approach to building scalable, reliable, and production-ready integrations, with a strong focus on Node.js, AWS, microservices, and event-driven architecture. Responsibilities Lead the technical approach to building an integration framework for AI-powered financial services products. Design and develop scalable integration solutions using Node.js, AWS, microservices, and event-driven architecture. Provide technical leadership to the integration team and support engineers in making strong architectural and implementation decisions. Work closely with stakeholders to understand integration requirements and translate them into robust technical solutions. Build and maintain integrations with third-party providers, accounting for quotas, rate limits, API constraints, retries, failure handling, and data consistency. Support architectural discussions and contribute to technical decision-making around integration patterns and event-driven systems. Help ensure solutions are suitable for regulated financial services environments, with a focus on security, reliability, auditability, and compliance. Requirements Around 10+ years of experience as a software developer, including significant experience building and operating production systems. Strong commercial experience with Node.js. Strong experience with AWS and cloud-native system design. Excellent knowledge of event-driven architecture. Experience designing and building microservices-based systems. Proven experience in technical leadership, especially within integration-focused or platform-oriented teams. Strong experience building integrations with external systems, APIs, and third-party providers. Experience working with high-volume data processing systems. Practical knowledge of handling API quotas, rate limits, provider limitations, retries, failure scenarios, and resilience patterns. Strong communication skills, with the ability to work effectively with both technical and non-technical stakeholders. Ability to take ownership of architectural decisions and be accountable for the technical direction of the solution. Fluency in Polish and advanced English communication skills, with the ability to take a stand and be held accountable for technical decisions. Nice to have Experience in FinTech, financial services, or another regulated industry. Experience working on AI-powered or data-intensive products. Experience integrating or embedding AI capabilities into software products. Practical experience using AI / LLM coding tools across the software development lifecycle. Why join us? Rite NRG is a vibrant outsourcing technology company driven by the Right People. We are dedicated to empowering businesses through innovative software solutions. We focus on building strong partnerships and providing top-notch software solutions that drive real business growth. Our business model revolves around collaboration and delivering impactful results for our clients. Join us, and be part of a team where great minds, Right Energy, and strong partnerships come together to shape the future of technology! Stable, long-term, full-time collaboration. Remote work within Poland and flexible working hours. High engineering culture with a focus on growth and learning. Multinational teams. Benefits: Private medical care, Multisport card, and workation (work for a week from Barcelona or elsewhere).