Senior .Net Developer

🏢 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: The offer is for a .NET Developer to design and build high-scale, internet-facing solutions in the travel-tech domain, focusing on a new .NET 8 architecture powering hotel booking platforms used by millions of users. The role covers end-to-end development, deployment, and production support in large-scale environments. It emphasizes performance, scalability, and high engineering standards within a collaborative team. 🗂️ Requirements: 4–5+ years commercial experience with .NET Core and C#, Strong knowledge of OOP, design patterns, algorithms, data structures, Experience building and deploying end-to-end solutions for internet-scale systems, Good understanding of SQL Server and Redis, Experience with containers and Kubernetes, Ability to ensure performance, reliability, scalability in production environments, Fluent English (written and spoken), CS/Engineering degree or equivalent practical experience 📃 Skills: C#, .NET, .NETCore, .NET8, SQLServer, Redis, Kubernetes, Containers, OOP, DesignPatterns, Algorithms, DataStructures 🏢 Description: Join a global B2C travel-tech team and build high-scale solutions that power smarter, more personalized hotel booking experiences for millions of users. RESPONSIBILITIES Design and develop a new architecture in .NET 8 for high-scale products. Build and evolve platform infrastructure used by millions of travelers ежедневно. Deliver end-to-end solutions: design, implementation, deployment, and production support. Collaborate with the team in a culture of transparency, continuous improvement, and innovation. Ensure performance, reliability, and scalability in large-scale production environments. Maintain high engineering standards: clean code, testing, documentation, and best practices. REQUIREMENTS 4–5+ years of commercial experience with .NET Core / C# . Strong CS fundamentals: OOP , design patterns, algorithms, data structures. Hands-on experience building and deploying end-to-end solutions for internet-scale problems. Good understanding of SQL Server and Redis . Experience with containers and Kubernetes . Strong communication skills, initiative, and teamwork mindset. High level of English (written and spoken). Education: CS/Engineering degree or equivalent practical experience. NICE TO HAVE Experience with NoSQL (e.g., Elasticsearch ). Experience with CI/CD . Background in large-scale production environments. 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. Adrianna Rudzka Junior IT Delivery Consultant adrianna.rudzka@speedapp.pl +48 884 271 647

🏢 Summary: B2B Software Engineer role focused on building and enhancing frontend applications with Angular and Flutter while supporting backend services in C#/.NET and SQL. The position involves developing RESTful APIs, ensuring application security and performance, and working in Agile sprints within a mostly remote setup. The role combines cross-platform development with backend integration and modern DevOps practices. 🗂️ Requirements: 3+ years of software development experience, Strong knowledge of Angular and Flutter, Strong knowledge of HTML, CSS, TypeScript, JavaScript, Experience with C#/.NET, Experience with SQL Server, Experience with NoSQL databases, Experience designing and implementing RESTful APIs, Experience with Git, Experience working in Agile methodologies, Ability to perform unit testing and debugging 📃 Skills: Angular, Flutter, HTML, CSS, TypeScript, JavaScript, C#, .NET, SQL, SQLServer, NoSQL, REST, Git, Agile, Azure, AWS, AzureFunctions, AzureDevOps, CI/CD, OAuth, JWT, IdentityServer, Ionic, Cordova 🏢 Description: Join a client’s company as a Software Engineer, working on frontend development with Angular and Flutter, supporting backend services with C#/.NET and SQL, and collaborating on user-friendly applications. RESPONSIBILITIES Develop, maintain, and enhance applications using Angular and Flutter Support backend development with C#/.NET and SQL Design and implement RESTful APIs and integrate them with frontend applications Ensure application security , performance , and scalability Perform unit testing , debugging, and participate in code reviews Collaborate in Agile sprints , contributing to planning, development, testing, and deployment Work closely with the Product team to translate requirements into technical solutions Stay up to date with emerging technologies and suggest process improvements REQUIREMENTS 3+ years of software development experience Strong knowledge of Angular , Flutter , HTML , CSS , TypeScript , and JavaScript frameworks Experience with C#/.NET and SQL Server (plus NoSQL) Familiarity with Git and Agile methodologies Strong problem-solving skills and attention to detail Excellent communication and teamwork skills A proactive mindset and eagerness to learn new technologies NICE TO HAVE Experience with Ionic or Cordova Knowledge of Azure or AWS cloud platforms Familiarity with Azure Functions, Azure DevOps, and CI/CD pipelines Experience with authentication frameworks (OAuth, JWT, IdentityServer) Interest in cross-platform development WHAT DO WE OFFER ON THIS PROJECT? Cooperation based on a B2B contract and rate: 90-100 PLN/hour / Cooperation based on a B2B contract. Hybrid work: (90% remote) from Kraków (1-2 times a month 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. Ilona Wójcik Junior IT Delivery Consultant ilona.wojcik@speedapp.pl +48 882 842 363

🏢 Summary: B2B remote role for a .NET Developer to design and maintain high-performance back-end services and scalable cloud solutions in AWS for industrial systems. The position focuses on API development, system integrations, and ensuring code quality through solid engineering and testing practices within a collaborative team. 🗂️ Requirements: Hands-on experience with AWS in production environments, Strong back-end engineering fundamentals, Experience with API design and integrations, Focus on performance and maintainability, Availability to work in PL/EU working hours 📃 Skills: .NET, C#, AWS, APIs 🏢 Description: For a client in the technology sector, developing industrial systems industry, we are looking for a position .Net Developer RESPONSIBILITIES Design, develop, and maintain high-performance back-end services using .NET (C#). Build scalable and resilient solutions using AWS services and databases. Collaborate with front-end developers and other engineers to integrate back-end services and APIs. Participate in code reviews, architectural discussions, and sprint planning. Contribute to keeping the codebase testable and reliable through solid unit/integration testing and good engineering practices. Work closely with the QA team to ensure quality and smooth releases (with less emphasis on personally owning E2E tests). Share knowledge and support less experienced team members as part of day-to-day collaboration. Stay up to date with relevant technologies and continuously improve the system. Tech Stack You’ll Be Working With •    Cloud: AWS •    Back-End: .NET (C#) •    Front-End (tooling/testing support): TypeScript (nice to have) REQUIREMENTS Hands-on experience with cloud environments in production (AWS preferred). Strong back-end engineering fundamentals: API design, integrations, performance, and maintainability. Ability to communicate clearly and work effectively in a collaborative team. Availability to work with a Poland-based team (PL/EU working hours). NICE TO HAVE Background in Electrical Engineering or a related technical field. Bachelor’s degree in Computer Science or a related field (or equivalent experience). Git and modern code review workflows. Experience working in an Agile environment. Familiarity with TypeScript/JavaScript. Familiarity with test tools like Playwright or Selenium. Engineering mentor mindset: enjoys sharing knowledge, coaching others, and reinforcing good habits through reviews, pairing, and pragmatic guidance. Understanding of QA methodologies and release processes. WHAT DO WE OFFER ON THIS PROJECT? Cooperation based on a B2B contract. 100% remote work. 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 Junior IT Delivery Consultant aleksandra.mazur@speedapp.pl +48 728 360 029

🏢 Summary: B2B contract role for a Senior Full-Stack Engineer to build and own features end-to-end, from Java/Spring backend services and data models to React-based frontend interfaces. The position involves contributing to shared UI components and backend architecture, performing cross-stack code reviews, and working in a cloud-native environment. 🗂️ Requirements: Strong backend experience with Java 21, Proficiency in Spring and Spring Boot, Experience with Hibernate, Solid frontend experience with JavaScript and TypeScript, Strong knowledge of React and Redux Toolkit, Good understanding of relational databases, especially MariaDB, User-level or higher Linux skills, Confident use of Git workflows, Ability to write well-tested, maintainable code, Advanced technical English, Experience with Kubernetes and cloud-native platforms, Ability to effectively use AI coding assistants and LLM tools 📃 Skills: Java, Spring, SpringBoot, Hibernate, JavaScript, TypeScript, React, Redux, MariaDB, SQL, Linux, Git, Kubernetes, AI, LLM 🏢 Description: Join our client's team as a Senior Full-Stack Engineer! RESPONSIBILITIES Own features end-to-end — from API and data model on the backend to the UI on the frontend Build and maintain backend services in Java, and rich interfaces in React Contribute to our shared UI component library and backend architecture alike Take part in code reviews across the stack — backend, frontend, and the glue in between REQUIREMENTS Strong backend skills in Java 21 with Spring / Spring Boot and Hibernate Solid frontend experience with JavaScript, TypeScript, React, and Redux Toolkit Good grasp of relational databases, especially MariaDB Linux skills at user level or above, plus confident Git workflows You write well-tested, maintainable code on both sides of the stack Advanced technical English for design, review, and documentation\ Proven experience with cloud-native platforms such as Kubernetes Comfortable using AI tools (coding assistants, LLMs) as part of your daily workflow — and the judgment to know when to trust them and when to think for yourself NICE TO HAVE Experience building software for telecommunication systems Knowledge of protocols like IPv4/6, DNS, BGP, DHCP, SR, and ZTP Data visualization libraries — Cytoscape.js, react-chartjs-2, MapLibre, or similar Storybook, mono-repo tooling (Lerna), or Webpack experience Automation tools such as Ansible or Terraform Understanding of Linux and Kubernetes networking (routing, iptables, CNI) WHAT DO WE OFFER ON THIS PROJECT? Cooperation based on a B2B contract and rate: 160-180 PLN/hour Hybrid work from Kraków (1 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, 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. Karolina Kizowska Senior IT Delivery Consultant karolina.kizowska@speedapp.pl +48 608 487 448

🏢 Summary: Senior Java Developer role involving full-cycle development from requirements and architecture to implementation and testing, with a focus on building and maintaining Java-based systems in cloud environments. The position includes developing new functionalities, maintaining existing code, and working with modern frameworks and containerized platforms. Hybrid B2B cooperation with competitive hourly rate and additional benefits. 🗂️ Requirements: Very good knowledge of Java 21, Experience with Hibernate, Experience with Spring, Experience with Spring Boot, Understanding of relational databases (MariaDB), Linux skills (user level or higher), Proficiency with Git, Advanced technical English, Experience with cloud-based architectures, Experience with Kubernetes, Comfortable using AI coding assistants and LLMs 📃 Skills: Java, Hibernate, Spring, SpringBoot, MariaDB, Linux, Git, Kubernetes, AI, LLM 🏢 Description: Join our client's team as a Senior Java Developer! RESPONSIBILITIES Participation in full development cycle: from requirements, specification up to architecture, development and system tests Implementation of new functionalities Maintenance of existing code REQUIREMENTS Very good knowledge of Java 21 Experience with Hibernate and Spring, Spring Boot frameworks Understanding relational databases, especially MariaDB Linux skills on user level or higher Knowledge and ability to work with version control system Git Advanced technical English skills Experience with cloud-based architectures and platforms such as Kubernetes Comfortable using AI tools (coding assistants, LLMs) as part of your daily workflow NICE TO HAVE Experience with making software for telecommunication systems Familiarity with concepts of SDN, Segment Routing, and OpenFlow Operational experience with enterprise-class routers and switches Knowledge of protocols such as IPv4/6, DNS, BGP, DHCP, SR and ZTP Knowledge of automation tools such as Ansible and Terraform Understanding of Linux and K8s networking (e.g. routing, iptables, CNI) WHAT DO WE OFFER ON THIS PROJECT? Cooperation based on a B2B contract and rate: 160-180 PLN/hour Hybrid work from Kraków or Warsaw (1 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, 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. Karolina Kizowska Senior IT Delivery Consultant karolina.kizowska@speedapp.pl +48 608 487 448

🏢 Summary: B2B opportunity for an experienced .NET Back-End Developer to build modern, scalable cloud-based solutions using C# and Azure. The role focuses on designing high-performance services, working with CosmosDB, and collaborating in an Agile team with exposure to AI-assisted development tools. This is a fully remote position with competitive hourly rates and long-term cooperation. 🗂️ Requirements: 5+ years of professional experience in .NET development, Strong experience with C#, Proven experience with Azure services, Experience with CosmosDB, Experience with TypeScript or JavaScript, Bachelor’s degree in Computer Science or related field, Ability to align with US-based team working hours, English language proficiency 📃 Skills: .NET, C#, Azure, CosmosDB, TypeScript, JavaScript, AI, Playwright, Selenium, Drupal 🏢 Description: For our client from the technology and industrial solutions sector, we are looking for a .NET Back-End Developer to join a talented development team working on modern, scalable software solutions. Responsibilities: Design, develop, and maintain high-performance back-end services using .NET and C#. Work extensively with Azure cloud services and CosmosDB to build scalable and resilient solutions. Collaborate with front-end developers, product owners, and other team members to integrate back-end services. Participate in code reviews, architectural discussions, sprint planning, and other Agile ceremonies. Use modern development tools and practices to improve productivity, code quality, and maintainability. Explore and apply AI-assisted tools where appropriate to support development, documentation, troubleshooting, and workflow efficiency. Contribute to improving development processes, engineering practices, and team knowledge sharing. Be a proactive problem-solver and continuous learner, staying current with relevant technologies and industry trends. Requirements: Application Development Experience: 5+ years of professional experience in .NET development. Cloud Development Expertise: Proven experience with C#, Azure services, and CosmosDB. Scripting / Front-End Knowledge: Experience with TypeScript preferred, or JavaScript. AI Tool Familiarity: Interest in or hands-on experience using AI tools to support software development, productivity, documentation, research, or troubleshooting. Educational Background: Bachelor’s degree in Computer Science or a related field. Flexibility: Ability to align somewhat with US-based team working hours. Communication: English language proficiency. Stack: Cloud: Azure, CosmosDB Back-End: .NET, C# Scripting / Tooling: TypeScript preferred, JavaScript acceptable Productivity / AI Tools: Familiarity with AI-assisted development or productivity tools is a plus Nice to have: Domain Knowledge: Background in Electrical Engineering or a related technical field. Background or interest in analog and mixed-signal hardware design. Knowledge of hardware or system simulation concepts. CMS Knowledge: Familiarity with Drupal. Test Automation Exposure: Familiarity with tools like Playwright or Selenium. Quality Mindset: Prior QA experience or understanding of QA methodologies is welcome. Offer: Cooperation based on a B2B contract and rate: 140-170 PLN/hour 100% remote work 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, Multisport card). 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.

🏢 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: Senior Fullstack Engineer role focused on building and scaling an AI-powered drive-thru platform for a QSR client. The position involves developing integrations with POS systems and digital menu boards, building data pipelines, and leading end-to-end integration projects in production environments. The engineer will also troubleshoot complex issues and drive technical delivery in a cloud-based ecosystem. 🗂️ Requirements: 7+ years experience in Python and JavaScript, Strong backend development skills, Strong software architecture skills, Experience delivering and deploying production projects, Proficiency with Async IO, Experience with React and Redux (RTK), Experience with CI/CD pipelines, Experience with cloud platforms (AWS/GCP/Azure), Experience with Linux environments, Experience with Docker and Kubernetes, Experience with 3rd party API integrations, Experience building Data Pipelines and ETL processes, BSc in Software Development or equivalent experience, 1+ year of technical leadership experience 📃 Skills: Python, JavaScript, React, Redux, CSS, AsyncIO, CI/CD, AWS, GCP, Azure, Linux, Docker, Kubernetes, APIs, ETL, SQL 🏢 Description: Join a QSR client as a Senior Fullstack Engineer and help develop an AI drive-thru platform that scales faster, smarter, and more accurately. RESPONSIBILITIES In this role, you will: Integrate with new POS systems and digital menu boards Build data pipelines to process restaurant menus Support existing integrations and pipelines Debug and solve complex customer issues Lead communication with integration partners to deliver the integrations Estimate, plan and deliver the integration projects Handle a large set of complex and diverse customer issues Create documentation for integrations REQUIREMENTS 7+ years experience in Python and JavaScript Strong backend development and software architecture skills Experience in developing and deploying multiple projects used in production Proficient with Async IO Experience with React, Redux (RTK), CSS modules Experience with CI/CD, Clouds (AWS/GCP/Azure), Linux, Docker, Kubernetes, 3rd Party API integrations Experience with Data Pipelines, ETL Prior experience working in startups BSc in Software Development or equivalent industry experience 1+ years of experience in technical leadership WHAT DO WE OFFER ON THIS PROJECT? Cooperation based on a B2B contract. 100% remote work. 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. Barbara Krawczyk Junior IT Delivery Consultant barbara.krawczyk@speedapp.pl +48 734 469 838