5Blue Software

Hi there,

We are currently seeking a Senior Java Engineer to join our growing teams.
 

About the project:

Our clients are enabling a world where everyone and everything can be intelligently connected. As the world’s leading wireless technology innovator, we continue to push the boundaries of what’s possible across devices and networks to enable next-generation experiences and drive digital transformation.
 

We deliver breakthroughs in 5G, Wi-Fi and AI. But that’s just the beginning. We design platforms, chipsets, software, tools, and services that help OEMs and developers bring those technologies into products and create experiences that change how we live and work.

And we do this at scale, building technologically advanced, in-demand end products that support everything from low- to high-complexity devices, helping us serve virtually every industry at the connected intelligent edge.
 

Requirements:

• 7+ years of experience with Java.
• Solid experience with the Spring framework, Spring Boot, Kotlin, Kubernetes.
• Experience in SQL, NoSQL, Big Data tools and microservices.
• Experience with Git and Maven.
• Deep understanding and strong Computer Science fundamentals: object-oriented design, data structures, application programming, and multithreading programming.
• Strong API Development experience with as many years of experience as possible.
• Upper-intermediate and higher English level.
• Team player with strong communication, interpersonal, and presentation skills.
• Stable long-term involvement in projects for 2+ years.

Responsibilities:

• Design and develop infrastructure and features for thousands of websites and over 1.4B users across the open web.
• Be responsible for large scale systems that generate billions of dollars, over 500,000 requests / second and 100TB of new data every day.
• Have end to end ownership: Innovate, design, build, ship, measure and maintain our backend services.
• Collaborate with the brightest software engineers.
• Leverage full CI/CD pipelines, A/B testing, and real Big Data environments to deliver high-impact solutions and observe their results in near real-time.
   

What we offer:

• Flexible Work Environment: Opportunity to work remotely.
• Premium Medical Insurance: Comprehensive health insurance to ensure your well-being.
• 1:1 English Classes: Individual English language training to enhance your communication skills.
• Great Team: Work with a supportive, collaborative, and dynamic international team.
• Equipment Provided: All necessary equipment supplied for efficient job performance.
• Annual Vacation: 18 days of paid vacation and 7 days of paid sick leave.
• Commitment to Hiring Ukrainians: We are dedicated to hiring Ukrainian talent and promoting Ukraine as a fantastic place to work.
• Flexible payment system, which allows you to withdraw funds in one click and has about twenty withdrawal options.

The recruitment process includes 4 interviews.

1. Initial meeting with HR — 30 min
2. Introduction + Technical interview (including coding task) — 1.5 hours
3. Architectural interview — 45-60 min
4. Final managerial interview — 1 hour

If you have any questions do not hesitate to ask us :)

Hi there,

We are currently seeking a Senior Java Engineer to join our growing teams.

About the project:

Our clients are enabling a world where everyone and everything can be intelligently connected. As the world’s leading wireless technology innovator, we continue to push the boundaries of what’s possible across devices and networks to enable next-generation experiences and drive digital transformation.

We deliver breakthroughs in 5G, Wi-Fi and AI. But that’s just the beginning. We design platforms, chipsets, software, tools, and services that help OEMs and developers bring those technologies into products and create experiences that change how we live and work.

And we do this at scale, building technologically advanced, in-demand end products that support everything from low- to high-complexity devices, helping us serve virtually every industry at the connected intelligent edge.

Requirements:

— 7+ years of experience with Java.

— Solid experience with the Spring framework

— Experience in SQL, NoSQL, and Big Data tools.

— Experience with Git and Maven.

— Deep understanding and strong Computer Science fundamentals: object-oriented design, data structures, application programming, and multithreading programming.

— Strong API Development experience with as many years of experience as possible.

— Upper-intermediate and higher English level.

— Team player with strong communication, interpersonal, and presentation skills.

— Stable long-term involvement in projects for 2+ years.

Responsibilities:

— Design and develop infrastructure and features for thousands of websites and over 1.4B users across the open web.

— Be responsible for large scale systems that generate billions of dollars, over 500,000 requests / second and 100TB of new data every day.

— Have end to end ownership: Innovate, design, build, ship, measure and maintain our backend services.

— Collaborate with the brightest software engineers.

— Leverage full CI/CD pipelines, A/B testing, and real Big Data environments to deliver high-impact solutions and observe their results in near real-time.

What we offer:

— Flexible Work Environment: Opportunity to work remotely.

— Premium Medical Insurance: Comprehensive health insurance to ensure your well-being.

— 1:1 English Classes: Individual English language training to enhance your communication skills.

— Great Team: Work with a supportive, collaborative, and dynamic international team.

— Equipment Provided: All necessary equipment supplied for efficient job performance.

— Annual Vacation: 18 days of paid vacation and 7 days of paid sick leave.

— Commitment to Hiring Ukrainians: We are dedicated to hiring Ukrainian talent and promoting Ukraine as a fantastic place to work.

— Flexible payment system, which allows you to withdraw funds in one click and has about twenty withdrawal options.

The recruitment process includes 4 interviews.

1. Initial meeting with HR — 30 min
2. Introduction + Technical interview (including coding task) — 1.5 hours
3. Architectural interview — 45-60 min
4. Final managerial interview — 1 hour
5.  

If you have any questions do not hesitate to ask us :)

Hi there,

We are currently seeking a Senior Java Engineer to join our growing team.

About the project:

Our clients are enabling a world where everyone and everything can be intelligently connected. As the world’s leading wireless technology innovator, we continue to push the boundaries of what’s possible across devices and networks to enable next-generation experiences and drive digital transformation.

We deliver breakthroughs in 5G, Wi-Fi and AI. But that’s just the beginning. We design platforms, chipsets, software, tools, and services that help OEMs and developers bring those technologies into products and create experiences that change how we live and work.

And we do this at scale, building technologically advanced, in-demand end products that support everything from low- to high-complexity devices, helping us serve virtually every industry at the connected intelligent edge.

Requirements:

— 7+ years of experience with Java.

— Solid experience with the Spring framework

— Experience in SQL, NoSQL, and Big Data tools.

— Experience with Git and Maven.

— Deep understanding and strong Computer Science fundamentals: object-oriented design, data structures, application programming, and multithreading programming.

— Strong API Development experience with as many years of experience as possible.

— Upper-intermediate and higher English level.

— Team player with strong communication, interpersonal, and presentation skills.

— Stable long-term involvement in projects for 2+ years.

Responsibilities:

— Design and develop infrastructure and features for thousands of websites and over 1.4B users across the open web.

— Be responsible for large scale systems that generate billions of dollars, over 500,000 requests / second and 100TB of new data every day.

— Have end to end ownership: Innovate, design, build, ship, measure and maintain our backend services.

— Collaborate with the brightest software engineers.

— Leverage full CI/CD pipelines, A/B testing, and real Big Data environments to deliver high-impact solutions and observe their results in near real-time.

What we offer:

— Flexible Work Environment: Opportunity to work remotely.

— Premium Medical Insurance: Comprehensive health insurance to ensure your well-being.

— 1:1 English Classes: Individual English language training to enhance your communication skills.

— Great Team: Work with a supportive, collaborative, and dynamic international team.

— Equipment Provided: All necessary equipment supplied for efficient job performance.

— Annual Vacation: 18 days of paid vacation and 7 days of paid sick leave.

— Commitment to Hiring Ukrainians: We are dedicated to hiring Ukrainian talent and promoting Ukraine as a fantastic place to work.

— Flexible payment system, which allows you to withdraw funds in one click and has about twenty withdrawal options.

The recruitment process includes 4 interviews.

1. Initial meeting with HR — 30 min
2. Introduction + Technical interview (including coding task) — 1.5 hours
3. Architectural interview — 45-60 min

4. Final managerial interview — 1 hour

    

If you have any questions do not hesitate to ask us :)

Hi there,
We are looking for a Senior Flutter / Android Developer to join our dynamic and growing team!
 

The ideal candidate is a passionate mobile engineer with a senior-level, ownership-driven mindset — someone who enjoys exploring new technologies, takes responsibility for mobile direction, and understands that strong products are built through collaboration and flexibility.
 

Your primary focus will be on Flutter and native Android development, building and evolving high-quality mobile applications. At the same time, we value curiosity and readiness to grow: you will have the opportunity to contribute to iOS development (even if your experience is currently limited) and gradually deepen your expertise in this area.

This role is perfect for a proactive team player who is comfortable stepping beyond a single platform when needed. Occasionally, you may also support Node.js backend tasks to help deliver mobile features and move the product forward.

If you enjoy having real influence, taking responsibility for mobile solutions, and continuously developing your skill set — we’d love to meet you!

Location: Europe, remote.
 

Requirements:

• 4-5+ years of overall commercial experience in mobile development.
• 4+ years of commercial experience with Flutter for cross-platform mobile applications.
• 2-3+ years of commercial experience in native Android development (Kotlin and/or Java).
• Basic hands-on experience with iOS development (Swift / SwiftUI)
• Strong understanding of mobile architecture patterns (MVC, MVVM, Clean Architecture) and best practices.
• Experience working with RESTful APIs, JSON, and mobile networking.
• Senior-level mindset with readiness to take ownership of mobile development across the product.
• Willingness to learn and grow in areas where experience is limited (especially iOS).
   

Advantages:

• Deeper experience with native iOS development.
• Experience collaborating closely with backend teams or basic backend exposure (e.g. Node.js).
• Experience mentoring or guiding other developers.
• Experience working on complex, enterprise-grade mobile applications.
   

Key Responsibilities:

• Take responsibility for mobile development across the product, acting as a go-to person for mobile-related decisions.
• Build and maintain high-quality mobile applications using Flutter and native Android.
• Contribute to iOS development tasks where needed and continuously deepen iOS expertise.
• Write clean, scalable, and maintainable code ensuring long-term stability and performance.
• Collaborate closely with designers, product managers, and cross-functional teams in a shared ownership model.
• Participate in architectural decisions and help define mobile best practices within the team.
• Integrate third-party services and ensure a smooth and responsive user experience.
• Optimize application performance across a wide range of devices.
• Stay up to date with modern mobile trends and proactively introduce improvements and best practices.
   

What We Offer:

• Flexible Work Environment: Opportunity to work fully remotely.
• Premium Medical Insurance: Comprehensive health insurance to support your well-being.
• 1:1 English Classes: Individual English language lessons to improve communication skills.
• Great Team: Supportive, collaborative, and dynamic international team culture.
• Equipment Provided: All necessary equipment supplied for efficient and comfortable work.
• Paid Time Off: 18 days of paid annual vacation and 7 paid sick leave days.
• Public Holidays: Ukrainian public holidays are preserved.
• Commitment to Hiring Ukrainians: We are dedicated to hiring Ukrainian talent and promoting Ukraine as a great place to work.
• Flexible Payment System: Multiple convenient payment options with easy fund withdrawal.
   

Does this position sound like a perfect match? We’re eager to hear from you!

Hi there,
We are looking for a Senior Flutter / Android Developer to join our dynamic and growing team!

The ideal candidate is a passionate mobile engineer with a senior-level, ownership-driven mindset — someone who enjoys exploring new technologies, takes responsibility for mobile direction, and understands that strong products are built through collaboration and flexibility.

Your primary focus will be on Flutter and native Android development, building and evolving high-quality mobile applications. At the same time, we value curiosity and readiness to grow: you will have the opportunity to contribute to iOS development (even if your experience is currently limited) and gradually deepen your expertise in this area.

This role is perfect for a proactive team player who is comfortable stepping beyond a single platform when needed. Occasionally, you may also support Node.js backend tasks to help deliver mobile features and move the product forward.

If you enjoy having real influence, taking responsibility for mobile solutions, and continuously developing your skill set — we’d love to meet you!

Location: Europe, remote.

Requirements:

• 5+ years of overall commercial experience in mobile development.
• 4+ years of commercial experience with Flutter for cross-platform mobile applications.
• 2+ years of commercial experience in native Android development (Kotlin and/or Java).
• Basic hands-on experience with iOS development (Swift / SwiftUI)
• Strong understanding of mobile architecture patterns (MVC, MVVM, Clean Architecture) and best practices.
• Experience working with RESTful APIs, JSON, and mobile networking.
• Senior-level mindset with readiness to take ownership of mobile development across the product.

• Willingness to learn and grow in areas where experience is limited (especially iOS).

   

Advantages:

• Deeper experience with native iOS development.
• Experience collaborating closely with backend teams or basic backend exposure (e.g. Node.js).
• Experience mentoring or guiding other developers.

• Experience working on complex, enterprise-grade mobile applications.

   

Key Responsibilities:

• Take responsibility for mobile development across the product, acting as a go-to person for mobile-related decisions.
• Build and maintain high-quality mobile applications using Flutter and native Android.
• Contribute to iOS development tasks where needed and continuously deepen iOS expertise.
• Write clean, scalable, and maintainable code ensuring long-term stability and performance.
• Collaborate closely with designers, product managers, and cross-functional teams in a shared ownership model.
• Participate in architectural decisions and help define mobile best practices within the team.
• Integrate third-party services and ensure a smooth and responsive user experience.
• Optimize application performance across a wide range of devices.

• Stay up to date with modern mobile trends and proactively introduce improvements and best practices.

   

What We Offer:

• Flexible Work Environment: Opportunity to work fully remotely.
• Premium Medical Insurance: Comprehensive health insurance to support your well-being.
• 1:1 English Classes: Individual English language lessons to improve communication skills.
• Great Team: Supportive, collaborative, and dynamic international team culture.
• Equipment Provided: All necessary equipment supplied for efficient and comfortable work.
• Paid Time Off: 18 days of paid annual vacation and 7 paid sick leave days.
• Public Holidays: Ukrainian public holidays are preserved.
• Commitment to Hiring Ukrainians: We are dedicated to hiring Ukrainian talent and promoting Ukraine as a great place to work.

• Flexible Payment System: Multiple convenient payment options with easy fund withdrawal.

   

Does this position sound like a perfect match? We’re eager to hear from you!

Hi there,

We are looking for a Senior Mobile Engineer with a strong Flutter focus to join our dynamic and growing team!

The ideal candidate is a passionate mobile engineer with a senior-level, ownership-driven mindset — someone who enjoys exploring new technologies, takes responsibility for mobile direction, and understands that strong products are built through collaboration and flexibility.

Your primary focus will be on Flutter, building and evolving high-quality mobile applications, while also being ready to make small, targeted changes in native Android and iOS codebases when needed — such as API integrations, UI elements, or platform-specific adjustments. You will have the opportunity to contribute to both iOS and native Android development and gradually deepen your expertise in these areas.

This role is perfect for a proactive team player who is comfortable stepping beyond a single platform when needed. Occasionally, you may also support Node.js backend tasks to help deliver mobile features and move the product forward.

If you enjoy having real influence, taking responsibility for mobile solutions, and continuously developing your skill set — we’d love to meet you!
 

Location: Europe only, Poland time-zone.

Requirements:

• 5+ years of overall commercial experience in mobile development.
• 4+ years of commercial experience with Flutter for cross-platform mobile applications.
• Practical experience with native Android development (Kotlin and/or Java) — enough to confidently make changes, debug issues, and integrate APIs.
• Basic hands-on experience with iOS development (Swift / SwiftUI) — ability to navigate the codebase and implement small changes.
• Interest and motivation to work with multiple mobile platforms, not just one.
• Strong understanding of mobile architecture patterns (MVC, MVVM, Clean Architecture) and best practices.
• Experience working with RESTful APIs, JSON, and mobile networking.
• Senior-level mindset with readiness to take responsibility for mobile development quality across the product.
• Willingness to learn and grow in areas where experience is limited

Advantages:

• Deeper experience with native iOS development.
• Experience collaborating closely with backend teams or basic backend exposure (e.g. Node.js).
• Experience mentoring or guiding other developers.
• Experience working on complex, enterprise-grade mobile applications.

Key Responsibilities:

• Take responsibility for mobile development across the product, acting as a go-to person for mobile-related decisions.
• Build and maintain high-quality mobile applications using Flutter and native Android.
• Contribute to iOS development tasks where needed and continuously deepen iOS expertise.
• Write clean, scalable, and maintainable code ensuring long-term stability and performance.
• Collaborate closely with designers, product managers, and cross-functional teams in a shared ownership model.
• Participate in architectural decisions and help define mobile best practices within the team.
• Integrate third-party services and ensure a smooth and responsive user experience.
• Optimize application performance across a wide range of devices.
• Stay up to date with modern mobile trends and proactively introduce improvements and best practices.

What We Offer:

• Flexible Work Environment: Opportunity to work fully remotely.
• Premium Medical Insurance: Comprehensive health insurance to support your well-being.
• 1:1 English Classes: Individual English language lessons to improve communication skills.
• Great Team: Supportive, collaborative, and dynamic international team culture.
• Equipment Provided: All necessary equipment supplied for efficient and comfortable work.
• Paid Time Off: 18 days of paid annual vacation and 7 paid sick leave days.
• Public Holidays: Ukrainian public holidays are preserved.
• Commitment to Hiring Ukrainians: We are dedicated to hiring Ukrainian talent and promoting Ukraine as a great place to work.
• Flexible Payment System: Multiple convenient payment options with easy fund withdrawal.

Does this position sound like a perfect match? We’re eager to hear from you!

Hi there,

We’re looking for a talented Senior Node.js Developer to help build the next generation of AI-driven finance solutions.

Location: Poland only.

About the project:

Our client provides an AI-powered platform that revolutionises corporate expense management by automating approval workflows, tracking real-time spending, and offering data-driven budgeting insights.

Designed for mid to large-sized businesses (200 to 10,000 employees), the solution ensures scalability and flexibility, enabling greater control over expenses while enhancing employee autonomy.

By replacing traditional expense reports, it streamlines financial processes, helping companies embrace digital finance through intelligent, integrated software!

Requirements:
— 7+ years of backend development experience with production systems
— Proficiency in Node.js for building scalable backend applications
— Strong experience with SQL databases (MySQL, PostgreSQL), including query optimization and performance tuning
— Familiarity with backend frameworks such as Express.js or similar
— Experience working in Agile environments
— Strong analytical and problem-solving skills for performance optimization and system efficiency
— Excellent collaboration and communication skills within cross-functional teams
— Experience with cloud services (AWS, GCP, Azure)
— Familiarity with microservices architecture and containerization (Docker, Kubernetes)
— Knowledge of CI/CD practices
— Strong experience with AI development tools and frameworks
— Upper-Intermediate English level or higher

Responsibilities:
— Design, implement, and maintain scalable, secure, and high-performance backend systems
— Build and manage RESTful APIs for seamless integration and smooth user interactions
— Optimize database queries, manage schemas, and ensure data integrity with large datasets
— Collaborate with frontend engineers, product managers, and cross-functional teams to deliver impactful features
— Contribute to system architecture design, ensuring scalability, resilience, and maintainability
— Participate in code reviews, refactor code for performance, and suggest optimizations
— Ensure backend processes follow security, compliance, and data privacy best practices
— Monitor and optimize backend performance for a smooth user experience

What we offer:
— Flexible Work Environment: Opportunity to work remotely
— Premium Medical Insurance: Comprehensive health insurance for your well-being
— 1:1 English Classes: Individual English language training to enhance communication skills
— Great Team: Supportive, collaborative, and dynamic international team
— Equipment Provided: All necessary equipment supplied for efficient job performance
— Annual Vacation: 18 days of paid vacation and 7 days of paid sick leave
— Commitment to Hiring Ukrainians: Dedicated to hiring Ukrainian talent and promoting Ukraine as a fantastic place to work
— Flexible Payment System: Allows you to withdraw funds easily with multiple options

Does this position sound like a perfect match? We’re eager to hear from you!