Jobs Java

ROLE OVERVIEW

We are looking for a Senior AI Software Engineer – Full Stack to design, build, and operate modern web applications and AI-powered solutions for the healthcare domain.

In this role, you will work across Front-end, Back-end, and DevOps, building AI-native features and agentic experiences using LLMs, retrieval, tool use, and structured workflows. You will also contribute to cloud-native services and help drive the adoption of modern AI engineering practices within the team.

CUSTOMER AND PROJECT

Our Customer is a leading provider of software solutions for the healthcare sector, operating across 19 countries with more than 9,000 employees.

The project focuses on developing and operating modern SaaS applications used in the healthcare domain. You will work on integrating AI-powered capabilities into products for clinicians and patients, while also contributing to cloud-native architecture, reliability, security, and developer productivity.

The role combines Java Full-Stack development, AI engineering, cloud-native technologies, and DevOps, with a strong focus on building practical AI features and agentic experiences that deliver real value to healthcare users.

TECHNOLOGY STACK

• Java, Spring Boot
• React, Angular
• Kafka, Terraform
• Kubernetes, Helm, ArgoCD
• Azure OpenAI, Anthropic SDK, MCP
• LLMs, AI agents, skills, workflows, AI pipelines and context engineering

RESPONSIBILITIES

• Design, develop, and operate modern web applications across Front-end and Back-end
• Develop scalable backend services using Java and Spring Boot
• Build AI-native features and agentic experiences using LLMs, retrieval, tool use, and structured workflows
• Develop AI agents, skills, and intelligent workflows that deliver practical value to healthcare users
• Design, evolve, and operate cloud-native services with a strong focus on reliability, security, and scalability
• Work with modern AI development tools and contribute to shared AI agents, skills, pipelines, and engineering workflows
• Collaborate closely with Product Management, UX, Architects, and other Engineering teams
• Contribute to engineering excellence and the adoption of modern AI engineering practices within the team

• Stay close to users and understand healthcare workflows to deliver outcome-driven solutions

   

REQUIREMENTS

• Several years of Senior-level Full-Stack development experience
• Strong commercial experience with Java and Spring Boot
• Solid Front-end expertise with React or Angular
• Experience with Kafka and Terraform
• Experience with cloud-native architectures and DevOps practices
• Hands-on experience with Kubernetes, Helm, and ArgoCD
• At least 1 year of hands-on commercial experience developing and integrating AI-powered features into software products
• Practical experience building AI agents, intelligent workflows, or automation solutions
• Experience with modern LLM ecosystems and AI platforms, such as Azure OpenAI, Anthropic SDK, or MCP
• Demonstrated practical use of AI tools in software engineering
• Experience with AI agents, skills, workflows, AI pipelines, or context engineering is a strong plus
• Degree in Computer Science, Software Engineering, or a comparable technical field
• Strong problem-solving, innovation, and proactive mindset

• Strong English communication skills

   

LANGUAGE REQUIREMENTS

English: B2 – Upper-Intermediate or above

Senior Java Developer

We are looking for an experienced Senior Java Developer to join a consultancy project in the Netherlands.

The ideal candidate has strong backend development skills, experience with cloud technologies, located in Netherlands and speaks Dutch.

Requirements

• 5+ years of experience in software development.
• Strong hands-on experience with Java, Spring Boot, Kotlin, Kubernetes, and similar backend/cloud technologies.
• Dutch language proficiency is required.
• Experience working in a consultancy environment would be a plus.
• Ability to work in a hybrid setup in the Netherlands.

Project Details

• Location: Netherlands.
• Work format: Hybrid, with some work-from-home days.

• Salary: €5,000–6,000 per month.

   

If you have strong Java development experience and are looking for a new opportunity, we'd be happy to hear from you!

Project Description

We are building a new platform for collecting and processing information across the bank and making it accessible through private and public cloud environments.

You will contribute to the platform’s development from the ground up, with a focus on Java development, SQL, automated testing, and code quality.

Responsibilities

• Develop clean, maintainable, and well-tested Java code.
• Write test cases and maintain documentation for users and support teams.
• Support and automate the development environment using Jenkins CI and Bash.
• Evaluate development tools, libraries, and approaches to improve software quality.
• Review code changes and provide constructive feedback to other developers.

Mandatory Skills

• At least 6 years of commercial Java development experience.
• Strong SQL knowledge and practical experience working with relational databases. Experience with Oracle or PostgreSQL is preferred.
• Strong problem-solving and debugging skills, including the ability to understand existing code, identify defects, and implement fixes.
• Ability to explain technical decisions and demonstrate coding skills during live coding exercises.
• English at B2 level or above.

Nice-to-Have Skills

• Experience with messaging systems such as RabbitMQ or Kafka.
• Experience with Docker and Kubernetes.
• Familiarity with Linux.

Recruitment Process

The selection process includes several stages on both our side and the client’s side:

1. CV Review: the project team reviews your experience and its relevance to the role.
2. Coderbyte Test: an online coding assessment.
3. Technical Interview: a technical discussion with our interviewer.
4. Project Management Interview (PMI): a discussion of your experience, communication skills, and fit for the project.
5. Karat Interview: the first client-side technical assessment.
6. Client Interview: the final interview with the client’s project team.

Please be prepared for coding assessments and live coding during the technical selection stages. As the process involves several interviews, it may take additional time to complete.

• Project Description:

  You will join a Regulatory Reporting Platform within a large US investment bank. The platform is responsible for collecting, processing, and transforming large volumes of data from multiple internal systems to produce regulatory reports for 240 jurisdictions worldwide. In total, the platform supports around 10,000 reports across a wide range of regulatory, compliance, financial, and risk reporting areas.
  This is a large-scale, business-critical data platform operating in a highly regulated environment, where data accuracy, quality, traceability, and timely delivery are essential. The team works on building and enhancing data pipelines, implementing reporting logic, ensuring data validation and reconciliation, and supporting the generation of complex regulatory outputs.
  The project is delivered by a global distributed team with colleagues located in Ukraine, Poland, and the US, offering close collaboration with engineers, analysts, and business stakeholders across multiple regions.

• Responsibilities:

  - Design, develop, and maintain solutions for a large-scale Regulatory Reporting Platform
  - Build and enhance data processing pipelines using Java and Apache Spark
  - Implement scalable logic for data ingestion, transformation, aggregation, and enrichment from multiple internal data sources
  - Develop and optimize batch processing jobs to support the generation of regulatory reports across multiple jurisdictions
  - Ensure high standards of data quality, validation, reconciliation, and consistency throughout the reporting lifecycle
  - Translate business and regulatory requirements into robust technical solutions
  - Collaborate with business analysts, QA engineers, and cross-functional teams to deliver reporting functionality
  - Investigate and resolve data and application issues in development, test, and production environments
  - Improve application performance, scalability, and reliability for high-volume data processing workloads
  - Contribute to the design and implementation of reusable components and engineering best practices
  - Participate in code reviews, testing, and release activities to ensure high-quality deliverables
  - Work closely with distributed teams across Ukraine, Poland, and the US in an agile delivery model
  - Support continuous improvement of the platform, including monitoring, troubleshooting, and operational stability

• Mandatory Skills Description:

  - 6+ years of commercial experience with Java
  + 2+ years of experience with Spark
  - Experience in designing and developing scalable, high-performance backend applications
  - Good knowledge of SQL and working with large datasets from multiple data sources
  - Strong problem-solving skills and ability to work effectively in a global distributed team

• Nice-to-Have Skills Description:

  - Experience in financial services, investment banking, or regulatory reporting projects
  - Familiarity with data quality, reconciliation, and control frameworks
  - Experience working with large-scale enterprise data platforms
  - Knowledge of cloud environments and modern data platform architectures
  - Understanding of CI/CD practices and automated deployment pipelines
  - Experience working in Agile / Scrum teams within a distributed global setup

• Languages:
  • English: C1 Advanced

Project Description:

You will join a Regulatory Reporting Platform within a large US investment bank. The platform is responsible for collecting, processing, and transforming large volumes of data from multiple internal systems to produce regulatory reports for 240 jurisdictions worldwide. In total, the platform supports around 10,000 reports across a wide range of regulatory, compliance, financial, and risk reporting areas.
This is a large-scale, business-critical data platform operating in a highly regulated environment, where data accuracy, quality, traceability, and timely delivery are essential. The team works on building and enhancing data pipelines, implementing reporting logic, ensuring data validation and reconciliation, and supporting the generation of complex regulatory outputs.
The project is delivered by a global distributed team with colleagues located in Ukraine, Poland, and the US, offering close collaboration with engineers, analysts, and business stakeholders across multiple regions.

Responsibilities:

- Design, develop, and maintain solutions for a large-scale Regulatory Reporting Platform
- Build and enhance data processing pipelines using Java and Apache Spark
- Implement scalable logic for data ingestion, transformation, aggregation, and enrichment from multiple internal data sources
- Develop and optimize batch processing jobs to support the generation of regulatory reports across multiple jurisdictions
- Ensure high standards of data quality, validation, reconciliation, and consistency throughout the reporting lifecycle
- Translate business and regulatory requirements into robust technical solutions
- Collaborate with business analysts, QA engineers, and cross-functional teams to deliver reporting functionality
- Investigate and resolve data and application issues in development, test, and production environments
- Improve application performance, scalability, and reliability for high-volume data processing workloads
- Contribute to the design and implementation of reusable components and engineering best practices
- Participate in code reviews, testing, and release activities to ensure high-quality deliverables
- Work closely with distributed teams across Ukraine, Poland, and the US in an agile delivery model
- Support continuous improvement of the platform, including monitoring, troubleshooting, and operational stability

Mandatory Skills Description:

- 6+ years of commercial experience with Java
+ 2+ years of experience with Spark
- Experience in designing and developing scalable, high-performance backend applications
- Good knowledge of SQL and working with large datasets from multiple data sources
- Strong problem-solving skills and ability to work effectively in a global distributed team

Nice-to-Have Skills Description:

- Experience in financial services, investment banking, or regulatory reporting projects
- Familiarity with data quality, reconciliation, and control frameworks
- Experience working with large-scale enterprise data platforms
- Knowledge of cloud environments and modern data platform architectures
- Understanding of CI/CD practices and automated deployment pipelines
- Experience working in Agile / Scrum teams within a distributed global setup

Project description

We are building the platform, which supports various information gathering and processing across the bank and providing access to this data through both private and public cloud approach. The solution will be built from the scratch using the latest technologies.

Responsibilities

Write good and well-tested code using Java

Write Test Cases and User/Supporter Documentation of your code

Development environment support (mostly automation using Jenkins CI, Bash)

Evaluate and adopt new development tools, libraries and approaches to improve quality

Perform peer code review of project codebase changes

Skills

Must have

At least 6+ years of experience in Java

Deep knowledge and usage of SQL (Oracle or PostgreSQL dialects is preferable)

It is essential for a candidate to have/be able to do livecoding, understand the code and fix it fast

Nice to have

Experience with Messaging Systems: RabbitMQ, Kafka, etc.

Experience with Kubernetes and Docker

Linux user

About Us

Smart Capital Center is an end-to-end, AI-powered platform for Commercial Real Estate (CRE) investment and financial management. We power real-time underwriting, asset management, and portfolio analytics through a combination of live data, workflow automation, and AI-driven insights.

Operating at the intersection of Generative AI, finance, and real estate, we are building systems that digitize and simplify complex financial workflows.

Our clients include leading institutions such as JLL, Pacific Life Insurance Company, and KeyBank. We are a lean, high-performance team building category-defining technology in a $17 trillion industry.

To learn more about our platform and vision, please visit our website.

The Role

We are looking for a Backend Software Engineer with strong experience in building scalable systems and a deep interest in AI-powered applications.

This is a high-impact, hands-on role where you will design and build backend services, integrate AI capabilities, and develop intelligent, agent-driven workflows used in real-world production environments.

You will work closely with product, AI, and engineering teams to deliver reliable, high-performance systems and automation features.

What You Will Do

Backend Development

• Design, build, and maintain backend services using Java (Spring Boot) and Python
• Develop scalable APIs and microservices for data-intensive applications
• Optimize system performance, reliability, and scalability
• Design efficient data models and handle complex integrations

AI & Intelligent Systems

• Implement and integrate AI-powered features into core products
• Design and build agent-based workflows for automation and decision-making
• Apply prompt engineering techniques to improve LLM outputs and behavior
• Work with modern AI frameworks to productionize intelligent systems

Cloud & Infrastructure

• Develop and deploy backend systems on AWS (EC2, S3, RDS, Lambda, etc.)
• Build resilient, scalable cloud-native services
• Contribute to system monitoring, logging, and reliability

System Design & Engineering Excellence

• Contribute to architecture, service boundaries, and system design decisions
• Write clean, maintainable, and well-documented code
• Ensure security, performance, and operational stability
• Continuously improve engineering quality and development practices

Collaboration

• Work closely with frontend, product, and AI teams
• Contribute to end-to-end feature delivery
• Participate in Agile development processes

Requirements

• 5+ years of backend software development experience
• Strong experience building and scaling backend systems in production

Core Technical Skills

• Strong experience with Java and Spring Boot
• Solid experience with Python
• Strong knowledge of SQL and database design (PostgreSQL preferred)
• Experience building REST APIs, microservices, and distributed systems
• Hands-on experience with AWS (EC2, S3, RDS, Lambda, etc.)
• Proficiency with Git and modern development workflows

AI & Modern Development Experience

• Experience with prompt engineering for LLM-based systems
• Practical experience building AI agent workflows in production
• Familiarity with frameworks/tools such as:
  • LangGraph
  • LangChain
  • LangSmith
  • or similar ecosystems
• Experience using AI-assisted development tools, such as:
  • Claude Code
  • Codex
  • OpenCode
  • or similar

Nice to Have

• Experience with vector databases or semantic search (e.g., Milvus)
• Knowledge of RAG (Retrieval-Augmented Generation) architectures
• Experience with CI/CD pipelines and DevOps practices
• Familiarity with event-driven architecture

• Experience with data processing pipelines or document AI systems

   

Why Join Us

• Work on cutting-edge AI-powered systems in a $17T industry
• Build real-world applications using LLMs, agents, and automation
• High ownership and autonomy with meaningful technical impact
• Opportunity to influence system design and engineering direction
• Fast-moving, execution-focused team with minimal bureaucracy
• Competitive compensation and flexible work environment

Who We Are

Adaptiq is a technology hub specializing in building, scaling, and supporting R&D teams for high-end, fast-growing product companies across a wide range of industries.

About the Product

Our client is an established technology company developing a sophisticated B2B SaaS platform that helps organizations streamline complex processes, manage digital operations, and deliver customized solutions to their customers.

The product serves a substantial international customer base and has evolved into a mature, feature-rich ecosystem with a strong focus on flexibility, automation, and scalability. Its architecture supports demanding production workloads, complex data processing, and a wide range of integrations with external systems and services.

The engineering team tackles exciting challenges around existing components, distributed systems, scalability, concurrency, and performance optimization, while continuously modernizing the platform and delivering new features in a fast-paced, AI-driven development environment.

About the Role

We are looking for a Senior Back End Engineer who combines strong backend expertise with an AI-first mindset, product thinking, and a high level of ownership. You will join a cross-functional R&D team working on the development and continuous improvement of a large-scale SaaS platform.

In this role, you will take ownership of critical back end components, design and implement scalable solutions, and address complex engineering challenges related to performance, concurrency, and system reliability. 

This is a fast-paced environment where engineers are empowered to make decisions, manage multiple priorities, and drive projects forward independently.

We are looking for an autonomous, proactive engineer who is comfortable navigating ambiguity, managing multiple priorities, and using modern development practices, including AI-assisted tools, to deliver high-quality solutions efficiently.
 

What You Will Do

• Design, develop, and maintain scalable backend services using Java and Spring Boot.
• Take end-to-end ownership of features, from loosely defined requirements to production-ready solutions.
• Design and optimize backend architecture, including concurrency, multithreading, databases, and distributed services.
• Leverage AI coding tools daily to accelerate development, solve complex problems, and improve engineering productivity.
• Manage multiple tasks and development workflows in parallel, effectively prioritizing and driving delivery.
• Proactively collaborate with product, architecture, and engineering teams to clarify requirements, resolve blockers, and move projects forward.
• Contribute beyond traditional backend boundaries when needed, including integrations, infrastructure-related challenges, and adjacent technologies.
• Maintain high engineering standards through automated testing, code reviews, and continuous improvement.
   

What We're Looking For

• 5+ years of professional software development experience, with strong hands-on expertise in Java.
• Solid experience with Spring / Spring Boot, relational or NoSQL databases, and backend system design.
• Strong understanding of multithreading, concurrency, and core Java concepts.
• Advanced, daily hands-on use of AI development tools such as Claude Code, Cursor, Codex, or similar, with practical experience integrating AI into real development workflows.
• Ability to critically evaluate AI-generated code, make sound technical decisions, and maintain high engineering standards.
• Proven end-to-end ownership, independence, and ability to turn ambiguous requirements into working solutions.
• Strong product mindset, proactive problem-solving, and the ability to manage multiple priorities in a fast-moving environment.
• Willingness to work across technical boundaries rather than limiting yourself to backend development.
• Strong communication skills and the ability to collaborate effectively in English.
   

Nice to Have

• Familiarity with front end technologies such as JavaScript, TypeScript, React
• Experience in fast-paced product development environments.
• Familiarity with REST APIs, event-driven architectures, and asynchronous processing
• Familiarity with AWS infrastructure, serverless components, or containerized environments
• Exposure to cloud infrastructure, CI/CD pipelines, or DevOps practices.
   

Why Join Us

• 20 days of paid vacation per calendar year, plus official public holidays in your country of residence.
• Full accounting and legal support in the countries where we operate.
• Fully remote work with a powerful workstation and access to a co-working space when needed.

About Our Client

Our client is a leading enterprise data platform company building an open, high- performance data lakehouse for AI and analytical workloads. The platform combines an intelligent SQL query engine, an AI-ready semantic layer, and an open catalog built on Apache Iceberg — enabling Fortune 500 companies across finance, energy, manufacturing, and logistics to unify, query, and govern data at massive scale across cloud and on-premise sources.

About the Role

We are looking for a Middle Software Engineer (1.5–3.5 years of experience) to join the sustaining engineering team for the data catalog and enterprise data management layer of a large-scale lakehouse platform — the services that automate data ingestion and optimize Apache Iceberg tables for existing customers. The team's mandate is to keep these services running reliably for current clients: investigating and fixing customer- reported issues, resolving defects, addressing performance regressions, and keeping dependencies and security patches current. This is a maintenance and support role, not a feature-development role.

This is a backend Java role in a multithreaded, distributed environment where stability and availability for production customers are the baseline expectations. You will work with hands-on mentorship from senior engineers and in daily collaboration with US-based engineering leads and support teams.

Responsibilities

• Investigate, reproduce, and fix customer-reported issues and defects in the catalog and data-management services (Java)
• Diagnose production problems from logs, metrics, and thread or heap dumps, and work with support teams and solution architects on customer escalations
• Address performance regressions and stability issues in multithreaded, distributed services
• Keep the services current: dependency and library upgrades, security patches, and compatibility fixes
• Write regression tests and small supportability improvements (logging, metrics, diagnostics) so issues are easier to catch and triage next time
• Take part in code reviews and follow the team's release and hotfix process
• Track and apply relevant upstream fixes from the Apache Foundation open-source projects used by the platform

• Communicate status, root causes, and blockers clearly in daily syncs with US-based engineering leads

   

Required Qualifications

• B.S. or M.S. in Computer Science or a related field
• 1.5–3.5 years of professional software engineering experience, preferably in backend or data-intensive systems
• Strong Java programming skills: solid command of the language, the JVM ecosystem, and standard tooling (Maven or Gradle, JUnit)
• Comfortable debugging and supporting production systems — reading logs and stack traces, reproducing issues, and finding root causes
• Good grounding in data structures and algorithms
• Working knowledge of multithreaded and asynchronous programming in Java (java.util.concurrent, executors, futures) and the motivation to go deeper
• Care for engineering quality — tests, code reviews, and an understanding of why availability, resiliency, and zero-downtime upgrades matter
• Comfort with a fast-moving environment, ownership of your work, and an eagerness to learn from and be mentored by senior teammates
• Comfortable with AI-assisted development workflows — using modern AI tools productively while critically validating their output
• English Upper-Intermediate or higher (B2+) — daily written and verbal communication with a US-based engineering team

• Availability to work EU business hours shifted 2–3 hours later for daily overlap with US West Coast mornings

   

Desired Skills

• C++ experience — reading or writing performance-sensitive native code
• Exposure to database internals or query planning
• Familiarity with distributed systems concepts: concurrency control, data replication, storage systems
• Apache Iceberg or other open table formats (Delta Lake, Hudi)
• Messaging systems: Kafka, NATS, or cloud pub/sub services

• Contributions to open-source projects (Apache projects especially valued)

   

Details

Engagement: Long-term contract

Location: Europe (EU / EEA / UK), remote

Working hours: EU business hours, shifted 2–3 hours later for daily overlap with the US West Coast team

Numerical Technologies LTD is a provider of custom software solutions and services specializing in risk, limits, and regulatory capital. We are currently looking for a Senior Java Developer to join our team.  

What you will be doing:

As part of the team, you will be participating in a project for a major US financial holding company. You will develop, maintain, and support software features, write scalable and fault-tolerant Java code, debug applications, and integrate with internal and third-party services. You will collaborate with the product team to meet requirements and ensure code quality through testing, code reviews, and system design.

Project: Modernization of a monolithic system into a microservices architecture.

What we’re looking for:

• 5+ years of experience in Java development, preferably in FinTech.
• Strong experience with Java and Spring Framework.
• Solid understanding of microservices architecture and design patterns.
• Proficient in SQL (Oracle, PostgreSQL).
• Experience with AWS.
• Python knowledge is a plus.
• Ability to test your own code to ensure quality.
• Capable of working autonomously and independently. 
• Bachelor's degree or higher required.
• Excellent communication and collaboration skills in an international environment.
• Upper-intermediate English level or higher.

What we offer:

• Competitive compensation depending on experience and skills.
• Regular assessments and salary reviews.
• Paid personal days.
• Mental health support program.
• Partial gym compensation.
• Language classes.
• Flexible working schedule.

We are looking for a Senior Full Stack Engineer (Java + React) for our partner, a growing software company based in Spain.

Our partner combines product development with client-facing engineering work. They build their own products in the search and AI space while also delivering software solutions for enterprise customers.

As part of an international engineering team, you will work on a live production platform used by real customers, contributing across both backend and frontend development and playing a key role in the evolution of its architecture.

This is a full-time remote contract position with an initial commitment of at least six months and the possibility of long-term extension.

Responsibilities

• Design, develop, and maintain backend services and APIs using Java and Spring Boot.
• Develop and maintain modern frontend applications using React.
• Build and deliver end-to-end features across the backend and frontend.
• Participate in a major platform migration toward a more secure and modern architecture.
• Contribute to architectural and technical design decisions.
• Transform business requirements into scalable technical solutions.
• Improve and refactor existing systems while maintaining production stability.
• Work with AWS infrastructure and cloud-based production environments.
• Collaborate closely with QA and cross-functional teams throughout the development lifecycle.
• Participate in Agile ceremonies and planning activities.
• Use AI-assisted development tools as an integral part of the engineering workflow.

Requirements

Technical Skills

• 6+ years of professional software engineering experience.
• Strong hands-on experience with Java and Spring Boot.
• Strong hands-on experience with React and modern frontend development.
• Strong hands-on experience with AWS and building or deploying production applications in AWS environments.
• Proven experience building and maintaining production-grade APIs and web applications.
• Solid understanding of software architecture, system design, and data modeling.
• Good understanding of frontend architecture, component-based development, and API integration.
• Experience with Docker, CI/CD pipelines, and modern cloud-native development practices.
• Experience working on live products with real production workloads.

AI & Modern Engineering Expectations

• Strong hands-on experience using AI-powered development tools such as Claude Code or similar as part of the day-to-day engineering workflow.
• Up-to-date understanding of modern AI capabilities and their practical application in software development.
• Ability to use AI tools to accelerate development, improve code quality, support architectural decisions, and increase engineering productivity.
• Experience with Spec-Driven Development (SDD) or similar methodologies that enable AI-native development workflows.
• Ability to identify opportunities where AI can add meaningful value to the product and its users.
• Comfortable working in an engineering environment where AI-assisted development is an integral part of the software development lifecycle.

Communication

• English level B2 or higher.
• Ability to communicate technical concepts clearly to both technical and non-technical stakeholders.
• Strong written communication and documentation skills.
• Comfortable working within distributed international teams.

Personal Qualities

• Strong ownership mentality and proactive approach.
• Ability to identify issues early and drive solutions independently.
• Open-minded and adaptable when evaluating technologies and approaches.
• Focus on code quality, maintainability, and long-term sustainability.
• Collaborative attitude and strong teamwork skills.

We are extending our Integrity teams and seeking for several Senior/Principal Backend Engineers for IC (Individual Contributor) and Tech Lead roles with strong expertise in Java, backend technologies and AWS serverless. This role is ideal for engineers passionate about designing and delivering intuitive, high-performing, and reliable user interfaces that support our award-winning educational platform.

This role is ideal for engineers passionate about building scalable distributed systems, data modeling, and delivering high-performing, reliable software solutions for our award-winning educational platform.

As a core contributor to our shared services team, you will play a key role in developing and enhancing the foundational systems that power both existing and new applications. This role is fully hands-on, requiring active involvement in coding, development, and implementation of technical solutions.

Responsibilities: 

• Lead and design, development, and optimization of scalable backend services using Java and serverless technologies (e.g., AWS Lambda, DynamoDB, etc).
• Architect and implement RESTful APIs and event-driven systems to support high-performance, distributed applications.
• Provide technical leadership to the team, ensuring alignment with architectural standards and best practices.
• Contribute to the development and integration of user-facing frontend components when needed.
• Analyze and optimize existing services to enhance performance, scalability, and cost-efficiency.
• Collaborate with cross-functional teams, including Architects, Product Managers, and engineering leads, to deliver innovative and impactful solutions.
• Mentor and guide junior developers, fostering a culture of continuous learning and knowledge sharing.
• Oversee the implementation and maintenance of CI/CD pipelines to ensure efficient and reliable software delivery.
• Maintain high standards of code quality through rigorous peer reviews, comprehensive testing, and adherence to industry best practices.
• Create comprehensive documentation for the developed shared components, including usage guidelines and examples.

Requirements:

• Over 10 years of experience in backend development with deep proficiency in Java and extensive hands-on experience with serverless frameworks (e.g., AWS Lambda, Google Cloud Functions).
• Solid understanding of frontend technologies, including React and Web Components, with the ability to contribute when needed.
• Expertise in designing and managing distributed systems, ensuring scalability, and advanced data modeling techniques.
• Demonstrated ability to lead and collaborate effectively with cross-functional teams and stakeholders across multiple locations, including distributed teams in Europe and the USA, to deliver impactful, high-quality solutions.
• Practical expertise in cloud technologies, specifically developing serverless applications on AWS using services such as Lambda, DynamoDB, API Gateway, SNS/SQS, and EventBridge.
• Deep understanding of software development best practices, including design patterns, test-driven development (TDD), and clean code principles.
• Experience implementing and managing CI/CD pipelines for automated build, deployment, and testing.
• Familiarity with modern DevOps practices and infrastructure-as-code (IaC).
• Proven ability to conduct comprehensive system design reviews, ensuring architectural alignment, scalability, performance, and adherence to best practices.
• Proven experience as a Tech Lead, with a strong track record of mentoring and coaching junior engineers, promoting skill development, and driving adherence to best practices to ensure team growth and technical excellence.
• Exceptional collaboration skills, working effectively across cross-functional teams, including Product Managers, Architects, and other engineering leads.
• Ability to communicate complex technical concepts clearly to both technical and non-technical stakeholders.
• Strong problem-solving skills, with a track record of troubleshooting and optimizing existing systems for performance, scalability, and cost efficiency.
• Ability to make strategic technical decisions while balancing project deadlines and business goals.

Experience: 10+ years
Project Duration: November 2, 2026 – March 31, 2027
Location: Hybrid, Kraków, Poland

About the Project

We are looking for a Senior Java Developer to build and maintain backend services and microservices using Java and Spring Boot. The role involves working with relational databases, containerization technologies, and Azure-based solutions in a collaborative development environment.

Responsibilities

• Develop backend services using Java and Spring Boot.
• Build, maintain, and support microservices.
• Work with relational databases, including PostgreSQL, Oracle, or Sybase.
• Deploy and manage applications using Docker and Kubernetes.
• Support solutions hosted on Microsoft Azure.
• Work in Unix/Linux environments.
• Collaborate with the development team to deliver project objectives.

Requirements

• 10+ years of professional experience.
• Strong knowledge of Core Java and Spring Boot.
• Hands-on experience with microservices architecture.
• Experience working with PostgreSQL or Oracle databases.
• Experience with Docker and Kubernetes.
• Experience with Microsoft Azure.
• Good understanding of Unix/Linux environments.
• Ability to collaborate effectively with other developers.

Tech Stack

• Java / Core Java
• Spring Boot
• Microservices
• PostgreSQL
• Oracle / Sybase
• Docker
• Kubernetes
• Microsoft Azure
• Unix/Linux

We are a Norwegian logistics-tech company that negotiates freight agreements and manages carrier relationships for e-commerce businesses of every size, from new startups to established brands. 

Profrakt negotiates freight agreements for more than 1,500 Norwegian online stores and businesses, from new startups to established brands. It pools their combined volume to get better prices than they could get alone. Customers deal with one partner and one agreement instead of many, while still getting access to carriers such as Bring, PostNord, Helthjem, Porterbuddy, Instabox and UPS. 

The Profrakt Portal is the customer’s daily workspace. Through it, businesses can:

• Book B2C and B2B shipments, from small parcels to pallets and heavy goods
• Have the system pick the best carrier for each shipment based on price, speed and service
• Print shipping labels, including cloud printing directly to connected label printers
• Track shipments and search, filter and export their shipment history
• Create return shipments and book pickups
• Manage a customer register, their account and a customizable dashboard
• Handle invoicing, shipment inquiries and support requests

As the platform grows, the team is moving selected backend services from Python to Java/Spring Boot. You’ll take part in that migration without disrupting customers.

You’ll also turn quickly built features into reliable production services and improve the data layer behind pricing, booking, tracking and invoicing.

Main Responsibilities:

- Design, build, and maintain scalable backend services and REST APIs using Java 17+ and Spring Boot

- Rewrite selected services from Python to Java, keeping behavior consistent and making sure nothing breaks during the transition

- Review AI-generated and rapidly prototyped code for correctness, security, performance, and maintainability, and turn it into production-grade software

- Design and optimize relational database schemas and queries (PostgreSQL/MySQL), with attention to performance and data integrity

- Improve the existing codebase through refactoring and test coverage.

Requirements:
- 5+ years of experience in Java development (Java 17+)
- Strong hands-on experience with Spring Boot (Spring Web, Spring Data JPA, Spring Security)
- Deep knowledge of PostgreSQL and/or MySQL: schema design, indexing, query plans, transactions, and migrations (Liquibase)
- Knowledge of object-oriented programming (OOP), design patterns
- Git, GitHub/Gitlab proficiency
- Problem-solving and communication skills
- Frontend development with React will be a big plus
- Experience with distributed systems and message brokers (Kafka, RabbitMQ)
- Familiarity with AI coding assistants and their typical failure modes is mandatory

We offer:
— Competitive salary;
— Experience with EU markets/clients;
— Health insurance;
— Fully Remote work;
— Long-term contracts;
— Highly qualified team;
— Paid vacation (22 working days) and sick leave ( 19 days);
— Partial reimbursement of courses, training, or seminars.

This role focuses on executing critical migration projects within the backend infrastructure. The Backend Infrastructure team is undertaking several large-scale migrations to modernize its systems, improve reliability, and reduce maintenance overhead. This TVC position will be instrumental in performing the hands-on work required for these migrations, working closely with the infrastructure team and other BackEnd teams.

Required Qualifications:

• Ability to work from our Warsaw office
• 5+ years of hands-on experience in Java programming.
• Strong communication and interpersonal skills, with the ability to collaborate effectively within a technical team environment.
• At least Upper-Intermediate level of both spoken and written English

• Bachelor’s degree in Computer Science, Software Engineering, or a related technical field, or equivalent practical experience.

   

Nice-to-Haves:

• Experience with build tools such as Gradle, Maven, or Bazel.
• Experience with building data pipelines.
• Knowledge of Google Cloud Platform (GCP) services.

Responsibilities

• Execute Migrations: Actively participate in and drive the execution of large-scale code and system migrations across various backend services. Some examples include: 
  • Importing or upgrading third-party dependencies.
  • Building projects on GoB(Gerrit-on-Borg).
  • Performing necessary code and dependency changes in backend projects
• Code Modification and Updates: Update and refactor existing codebases (primarily Java) to align with new libraries, platforms, and infrastructure.
• Testing: Work with the Infrastructure team to create a testing plan for migrations to ensure that changes do not break running services and execute the test plans.  
• Collaboration: Work closely with the  Backend Infrastructure team and other BE software engineers to understand migration requirements, plan execution strategies, and ensure smooth transitions with minimal disruption.
• Problem Solving: Investigate, debug, and resolve technical issues and complexities encountered during the migration processes.
• Documentation: Maintain clear and concise documentation for migration plans, processes, changes made, and outcomes.
• Best Practices: Adhere to software development best practices, ensuring code quality, and follow established guidelines for infrastructure changes.

We offer:

• Opportunity to work on a global product used by 100+ million users worldwide.
• Competitive compensation package, including 20 paid vacation days and paid sick leave.
• Full-time office-based work (5 days per week) in a modern, comfortable office in Warsaw.
• Flexible working hours with a healthy work-life balance.
• Private medical insurance.
• English classes with a native speaker and wellness activities, including online yoga.
• Paid tech training and other activities for professional growth;
• Modern, comfortable office and a friendly, supportive engineering culture.
   
  If your qualifications and experience match the requirements of the position, our recruitment team will reach out to you in a week maximum. Please rest assured that we carefully consider each candidate, but due to the amount of applications, the review and further processing of your candidacy may take some time.