Jobs Java

About Strim Duo:

Strim Duo is a creative and high-tech game and digital product studio headquartered in Limassol, Cyprus. The company provides a wide range of services, including social game development, product engineering, UX/UI design, custom software solutions, mobile applications, and post-launch product support.

Strim Duo helps partners create engaging and highly effective game content: from social and arcade games to MMORPGs and children’s apps, integrating advanced monetization mechanics and social network features (strim-duo.com)

What We’re Looking For

— Strong understanding of OOP, software engineering best practices, and API design;
— Experience with Java & Spring ecosystem;
— Solid knowledge of distributed systems and microservices architecture;
— Hands-on experience with containerization and orchestration (Kubernetes, Helm);
— Understanding of CI/CD principles and modern delivery pipelines;
— Experience with cloud platforms (AWS preferred);
— Familiarity with Infrastructure as Code (Terraform or similar);
— Proficiency in SQL and relational databases;
— Experience with monitoring and observability tools (Grafana, Prometheus, Kibana);
— Proactive mindset, ownership mentality, and strong problem-solving skills;
— English level: Intermediate+ (sufficient for daily communication);

What You Will Be Responsible For

— Active feature development and continuous improvement of backend services;
— Full ownership of services: from design and development to deployment, support, and bug fixing;
— Participation in architecture design and technical decision-making;
— Building and evolving systems with a focus on scalability, reliability, and sustainability;
— Improving observability: monitoring, logging, alerting;
— Working with CI/CD pipelines and deployment processes;
— Close collaboration with cross-functional teams;
— Documenting technical decisions and sharing best practices;

What we offer

— Corporate psychologist;
— Gifts for significant occasions;
— Legal support;
— Flexible working hours;
— Direct access to C-level and opportunity to suggest new business ideas and drive changes.

Project Description

The client provides a reimbursement platform available for companies with mobile employees who are traveling places for their day-to-day job. They have solutions for Small and Medium Businesses, Mid-size companies and Enterprises to enable them to manage the reimbursement by streamlining and optimizing calculation process, control cost by using insight based on the rich user data aggregated through their Mobile app.

Job Description

We are looking for a talented Senior Java Software Engineer to take part in building a tactical solution within a planed way to an Enterprise Data Platform.

• Team player, accountable, dedicated and passionate.
• 6+ years of experience coding in Java (must).
• Experience of team/tech leading
• Self-learner 
• Experience with system design and data structures.
• Experience in designing and building multi-tenant and scalable microservice systems
• Experience working in a containerized environment with Kubernetes (Advantage)
• Experience in relational databases (Postgres ) 
• Experience with cloud technologies (AWS/Azure)
• Experience with using queues and messaging systems - Kafka, RabbitMQ - (Advantage)
• Experience in building deployment pipelines using Jenkins and Kubernetes - (Advantage)

Job Responsibilities

• Become a valued member of an autonomous, cross-functional agile team.
• In cooperation with solution architect, lead developer design, develop and deploy Java services focusing on high availability, low latency, scalability and high throughput.
• Collaborate closely with other engineers, product owners and designers, to identify and solve challenging problems.
• Take full responsibility and ownership from conception, development, quality to post-deployment.

Overview:
We are looking for a Senior Backend Engineer to lead the development of core backend services within a modern microservice infrastructure that powers mobile and embedded clients. This is a senior, hands-on role with architectural ownership, ideal for an engineer who enjoys building scalable distributed systems, designing secure and reliable APIs, and mentoring other developers. You will drive technical decisions and collaborate closely with architects, frontend engineers, and product teams to deliver future-proof backend solutions.

Responsibilities:

• Lead the design and development of backend services using Java in a Docker/Kubernetes-based environment;
• Drive architectural improvements and establish backend best practices across the platform;
• Design, implement, and optimize event-driven systems based on Kafka;
• Build secure, scalable RESTful APIs for internal and external consumers;
• Design and query complex data models using PostgreSQL, with strong focus on performance and reliability;
• Collaborate closely with frontend and product teams to deliver features end-to-end, from concept to production;
• Ensure system reliability and observability through logging, tracing, and monitoring;
• Enable integrations with data pipelines and ML-powered services as part of data-driven and AI initiatives;
• Mentor junior engineers, conduct code reviews, and support team-wide technical growth.

Requirements

• 5+ years of professional experience in backend development within microservice and cloud-native environments;
• Strong production experience with Java (e.g., Spring Boot or similar frameworks);
• Python experience is a plus, especially for data pipelines, ML integration, or scripting tasks;
• Deep understanding of:
  • Kafka and event-driven architectures;
  • PostgreSQL, including advanced schema design and query optimization;
  • Secure API design and implementation (OAuth2, HTTPS, mTLS).
• Hands-on experience with Docker, Kubernetes, and CI/CD pipelines in production;
• Proven ability to lead cross-functional technical initiatives and make architectural decisions;
• Demonstrated experience mentoring or guiding less experienced engineers;
• Exposure to video streaming backends or media platforms is a plus;
• Strong interest or background in ML- or data-driven applications;
• Bonus: Experience with observability stacks (e.g., Prometheus, Grafana) or real-time analytics systems.

Proxy-Seller is about people, ideas, and constant forward motion.
For over a decade, we’ve been developing powerful solutions for working with large volumes of data. Under the hood — scalable systems and intelligent infrastructure processing millions of requests and petabytes of traffic every month.
Our team includes 140 specialists from 4 continents, united not only by a shared goal but also by a desire to improve the product, processes, and results every single day.

Core languages and frameworks:

Java
Groovy, working with the Spring Boot framework;
Spock Framework — for Groovy testing;
Project Reactor (reactive programming);
Functional programming in Java;
Vert.x;
RESTful API.

Databases and caching: MongoDB (version 4.4+), Redis.
 

Tools and environment:
Git, GitHub, Gradle, Docker, Grafana, Prometheus (possibly via Spring Boot Actuator), SBE (Agrona is not mandatory, we’ll teach).

Your future responsibilities:
- Maintain and optimize the code of high-load applications — to keep everything running like clockwork;
- Quickly fix bugs, improve existing features, and enhance system stability;
- Refactor code mercilessly to legacy, keep frameworks up-to-date;
- Optimize performance: databases, queries, cache, logic - everything that affects speed;
- Develop new features and integrate modern frameworks;
- Write microservices using Spring Boot, grow your skills in Vert.x and other technologies;
- Collaborate closely with the team: frontend, QA, DevOps, and product managers.

What you need to join:
- Experience in writing code and tests;
- At least 2 years of commercial experience with Groovy;
- Experience working with high-load systems;
- Ability to clearly express your ideas and implement them;
- Willingness to work with someone else's code and write clean, maintainable code;
- Team communication and constructive collaboration skills.

It would be a plus: 
- Experience in mentoring or leading a team;
 

Our work approach:
At Proxy-Seller, we don’t just write code — we create solutions that change the industry.
We use cutting-edge tools to ensure that every line of code becomes part of an innovative solution.
- IntelliJ IDEA + AI Pro - a development environment enhanced with built-in AI;
- Sentry — for instant detection of production errors;
- Grafana + Loki + Prometheus — a complete real-time view of our systems;
- Our apps live and breathe in Docker containers, providing exceptional portability and isolation;
- Kubernetes — for scaling, isolation, and self-healing;
- Our GitHub organization is more than version control - it’s a hub of intellectual capital, including private repositories for Docker images and Node.js modules. With GitHub Actions, we’ve fully automated CI/CD processes, turning every code commit into part of a seamless, instant delivery cycle. This lets us focus on innovation instead of routine.

What we offer:
- Freedom of action — no micromanagement, we trust your professionalism;
- Minimal bureaucracy — maximum value;
- Clear and effective communication — no unnecessary meetings;
- Support from a strong team — constructive code reviews, help without judgment;
- Real cases in high-load systems and working with a modern tech stack;
- Ability to use AI to automate daily tasks;
- Encouragement of initiative and autonomy;
- Competitive salary in USD (fixed + performance bonuses). Transparent processes and stable payouts twice a month;
- Paid vacation, sick leave, and days off;
- Compensation for relevant courses and training, with the possibility to change tech stack on your initiative;
- Opportunity for paid overtime (completely optional).

*We usually review applications within 3-5 business days
We share feedback if we’re able to move forward together. If this role isn’t the right match for now, we’ll keep your resume in our database and gladly reach out when a suitable opportunity comes up

We look forward to receiving your application :)

Project Description:

The SEM product is embedded within the Geosciences Suite of Applications. This application has multiple views consisting of both 2D and 3D visualizations. The current data visualization is not sufficient for what we would like it to be. This role is expected to work with the lead and the product owner to understand the current shortcomings, investigate and research potential solutions, propose these solutions to the teams, and then work on the implementation of the agreed upon work. To get to this stage, the developers will also need to learn the inner workings of the visualization framework within Geoscience.

Responsibilities:

• Design, develop, and maintain graphics-intensive modules within the Geoscience platform using Java and OpenGL.
• Implement advanced 2D and 3D visualization features for seismic, geological, and geospatial data.
• Optimize rendering performance and ensure cross-platform compatibility, particularly in Linux environments.
• Collaborate with geoscientists and software engineers to translate domain-specific requirements into technical solutions.
• Participate in code reviews, testing, and documentation to maintain high-quality software standards.
• Stay updated with the latest developments in graphics technologies and geoscience applications.

Mandatory Skills Description:

• Bachelor's or Master's degree in Computer Science, Geoscience, or a related field.
• 5+ years of professional experience in Java development with a focus on graphics programming.
• Proficiency in OpenGL and related graphics libraries for rendering complex datasets.
• Strong experience working in Linux environments, including shell scripting and system optimization.
• Excellent problem-solving skills and the ability to work collaboratively in a multidisciplinary team.

Nice-to-Have Skills Description:

• Experience with geoscience software platforms.
• Familiarity with geoscience data formats and visualization techniques.
• Knowledge of additional programming languages such as C++ or Python.
• Understanding of GIS technologies and spatial data analysis.
• Experience with agile development methodologies and version control systems like Git

Languages:

English: B2 Upper Intermediate

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

What will you be doing?

As part of the team, you will be participating in a project for a major US financial holding company. You will be helping build new software features, support, and maintain existing ones. You will be writing scalable and fault-tolerant code, debugging programs, and integrating applications with internal and third-party services. You will be collaborating closely with the product team to understand the system’s functional and non-functional requirements and contribute to code quality through unit testing, integration testing, code reviews, and system design using Java to build robust software that aligns with business needs.

What we’re looking for:

• 4+ years of experience in Java development, preferably in FinTech.
• Good knowledge of Core Java, concurrency, multi-threading, IO/networking, 
• Strong understanding of design patterns.
• Proficient in SQL, capable of reading and understanding complex queries and procedures.
• Python knowledge is a plus.
• Ability to test your own code to ensure quality.
• Capable of working autonomously and independently. 
• University diploma (Bachelor’s degree or above) 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’re looking for a Senior Java Engineer with Python&Golang skills to join our team.

Our client is defining the future of cybersecurity through our XDR platform that automatically prevents, detects, and responds to threats in real time. Singularity XDR ingests data and leverages our patented AI models to deliver autonomous protection.

Our team is responsible for the backend part for the main product line  - securing tens of millions of devices across the globe of all kinds of OS (Windows, Linux, macOS), and processing billions of security events every day.

You'll be joining a team with a significant impact on how our customers' environments (incl. 4 of Fortune10 companies, hundreds of Global2000 or governments) are protected, how they interact with agents, gain visibility into their security posture, and understand the risks and act upon them.

What will you do?
Design, develop and support backend system serving for endpoint security
●      Help us with initiatives around moving our services to a new deployment model.
●      Tuning and adjusting our services to work with new CPU architectures.
●      Improving the observability for our services.

• Requirements: 
  7+ years of extensive software engineering experience, including proven expertise in developing large-scale distributed systems and microservices architecture, with a focus on performance, scalability and reliability
• Proficiency in Java
• knowledge of Golang and Python 
• Experience with cloud platforms (AWS and/or GCP) and Kubernetes (must)
• Experience with Kafka or similar solutions is a plus

We are looking for 2 strong Java developers for the new startup we start working with, with at least 3+ years of experience as a back-end engineer.

We need an excellent knowledge of:

- Java, JVM and the ecosystem

- Strong Databases experience( SQL, NoSQL)

- Strong analytical thinking

- Ability to be a good teamplayer, communicate and contribute

- Databases optimizations knowledge is a big plus
- AWS experience is a big plus

We would prefer candidates who are ready to move fast, as we are ready to hire ASAP, screening and processing can be done in a fast track for this opening!



About us: Mindecs - is an outstaffing/outsourcing company that's working with leading brands and startups.

N-iX is a software development service company that helps businesses across the globe develop successful software products. During 20 years on the market and by leveraging the capabilities of Easter Europe talents, the company has grown to 2000+ professionals with a broad portfolio of customers in the area of Fortune 500 companies as well as technological start-ups. With its headquarters in Lviv, Ukraine, the company also has multiple development offices in the East European region and representative entities in the United States of America, Sweden, and Malta.

Our client - one of the world's largest fashion retailers selling in 215 markets through its online platform or its 6,477 stores in 95 markets. By working closely together as a single company globally focused on the key elements of fashion production – design, manufacture, distribution, and retail. All the production is founded on three pillars – flexibility, digital integration, and sustainability.

Responsibilities:

• Be a part of the Scrum team and deliver value to users by developing high-quality functionality
• Maintain and extend already existing applications
• Actively participate in refinements, plannings, set estimations and follow commitments
• 80% unit tests coverage is a must
• Follow Eslint, Prettier, SonarQube and other code quality rules
• Follow code review processes

Requirements:

• 4+ years of Java development, Maven
• 2+ years of Spring framework and building Spring web applications
• Familiar with the microservices concept
• Experience developing REST interfaces
• Design, coding and debugging skills
• OOP, OOD, and Design Patterns proficient
• Working knowledge of NoSQL (MySQL) DB technologies – Mongo DB
• Understanding of Kafka, Kafka streaming
• Familiar with GrayLog, Grafana
• Strong knowledge of Unit testing
• Basic understanding of Scrum and main aspects of working in Agile environment

Nice to have:

• Working experience in an Agile environment, a clear understanding of Agile methodologies mindset, and development practices applicable to them
• Excellent communication skills, product-oriented mindset, focus on team results, willingness to continuous personal and team improvements
• Upper-Intermediate English level (there will be a lot of communication with the client)

We offer*:

• Flexible working format - remote, office-based or flexible
• A competitive salary and good compensation package
• Personalized career growth
• Professional development tools (mentorship program, tech talks and trainings, centers of excellence, and more)
• Active tech communities with regular knowledge sharing
• Education reimbursement
• Memorable anniversary presents
• Corporate events and team buildings
• Other location-specific benefits

*not applicable for freelancers

Softsich is a young and ambitious international product tech company that develops scalable B2B digital platforms. We are looking for a Backend Java Tech Lead who will take technical ownership of the backend team working with a microservices, high-load architecture.

This role is about leadership, architecture, and responsibility for the technical direction of the platform.

Your key responsibilities will include:

• Lead the backend team technically, ensuring architectural vision and technical standards.
• Design, implement, and maintain high-load, scalable backend services using Java and Spring Boot.
• Drive technical decisions and take full ownership of architectural solutions.
• Ensure high code quality via best practices, reviews, and automation.
• Optimize system performance and reliability across microservices.
• Work with event-driven architectures and distributed systems.
• Mentor developers, support skill development, and foster collaboration.
• Collaborate with cross-functional teams to deliver reliable and scalable solutions.

It’s a match if you have:

• 5+ years of commercial experience with Java (17+/21) and Spring Boot.
• Strong knowledge of the Spring ecosystem: Web, Security, Data, Scheduler, WebFlux.
• Hands-on experience with microservices and high-load architectures, event-driven systems.
• Practical knowledge of CI/CD, containerization (Docker), and deployment to Kubernetes (EKS).
• Solid experience with Apache Kafka (producers/consumers, distributed topics, retry and error handling).
• Experience working with databases: PostgreSQL, MongoDB / AWS DocumentDB, SingleStore.
• Experience in designing and optimizing REST APIs.
• Experience with monitoring and logging tools: Grafana, Prometheus, Micrometer, ELK.
• Experience in technical leadership or mentoring engineering teams.
• Ability to make and own architectural and technical decisions.
• Strong communication skills, teamwork mindset, and analytical thinking.
• English level — Upper-Intermediate.

What we offer:

– Flexible schedule and remote format or offices in Warsaw.

– 24 paid vacation days, sick leaves, and health insurance (UA-based, other locations in progress).

– A supportive, friendly team where knowledge-sharing is part of the culture.

– Coverage for professional events and learning.

– Birthday greetings, team buildings, and warm human connection beyond work.

– Zero joules of energy to the aggressor state, its affiliated businesses, or partners.

Send over your CV now — we’d love to get to know you better!

Project description

The SEM product is embedded within the Geosciences Suite of Applications. This application has multiple views consisting of both 2D and 3D visualizations. The current data visualization is not sufficient for what we would like it to be. This role is expected to work with the lead and the product owner to understand the current shortcomings, investigate and research potential solutions, propose these solutions to the teams, and then work on the implementation of the agreed upon work. To get to this stage, the developers will also need to learn the inner workings of the visualization framework within Geoscience.

Responsibilities

Design, develop, and maintain graphics-intensive modules within the Geoscience platform using Java and OpenGL.

Implement advanced 2D and 3D visualization features for seismic, geological, and geospatial data.

Optimize rendering performance and ensure cross-platform compatibility, particularly in Linux environments.

Collaborate with geoscientists and software engineers to translate domain-specific requirements into technical solutions.

Participate in code reviews, testing, and documentation to maintain high-quality software standards.

Stay updated with the latest developments in graphics technologies and geoscience applications.

Skills

Must have

Bachelor's or Master's degree in Computer Science, Geoscience, or a related field.

5+ years of professional experience in Java development with a focus on graphics programming.

Proficiency in OpenGL and related graphics libraries for rendering complex datasets.

Strong experience working in Linux environments, including shell scripting and system optimization.

Excellent problem-solving skills and the ability to work collaboratively in a multidisciplinary team.

Nice to have

Experience with geoscience software platforms.

Familiarity with geoscience data formats and visualization techniques.

Knowledge of additional programming languages such as C++ or Python.

Understanding of GIS technologies and spatial data analysis.

Experience with agile development methodologies and version control systems like Git

Languages

English: B2 Upper Intermediate

One of the world's largest providers of products and services to the energy industry has a need to develop and support enterprise information system in Oil & Gas domain.
Product being developed is a cloud solution for interpretation of geological and geophysical data. Project is based on SCRUM methodology.
Our project is stable, long-term and constantly adopts new technologies such as newest Java and Eclipse RCP versions, cloud and GPU computing, microservices architecture and other innovative frameworks.
Work supposes close cooperation with Customer team located in Houston and following Agile principles.
Our team is senior, supportive and friendly.

• Responsibilities:

  • Collaborate closely with geophysicists, data scientists, and software engineers to
  translate scientific domain requirements into robust on-prem or Cloud software
  solutions.
  • Design, develop, and maintain high-performance applications for geophysical and
  geological data analysis, interpretation and visualization (e.g., seismic, horizon,
  fault, velocity model, etc.)
  • Present architectural designs and technical proposals to the architecture review
  board.
  • Ability to break down development tasks and lay out clear implementation
  roadmaps.
  • Implement and optimize computation algorithms
  • Design and develop both thin and thick client applications that interact with cloud-
  based microservices.
  • Ensure high code quality through unit testing, code reviews, security hardening and
  continuous integration with other domain tools
  • Provide technical support and lead user troubleshooting sessions to resolve issues
  and ensure smooth operation of DSG application.
  • Mentor junior developers and actively contribute to architectural and
  implementation decisions.
  • Embrace Agile/Scrum methodologies, delivering and demonstrating working
  solutions at the end of each sprint
  • Stay current with emerging technologies and trends in geophysical computing and
  software development.

• Mandatory Skills Description:

  5+ years in Java development
  Strong Java Core knowledge

We are a U.S.-based fintech startup operating in the investment and financial services space. Our distributed teams work across Poland, the United States, and Ireland, collaborating on technology-driven solutions related to stocks and investments.

Security, compliance, and the responsible handling of sensitive financial data are central to how we operate, as we build scalable products in a regulated environment.

Responsibilities

- Develop high-quality Java microservices using Spring Boot.
- Build Kafka producers, consumers, and stream-processing apps.
- Design event-driven architectures with reliability and performance.
- Implement service resiliency patterns such as retries and circuit breakers. - Collaborate on distributed system design and integration.

• Ensure logging, tracing, and monitoring of backend services.

• Support performance tuning and root cause analysis.

   

• Skills
  - Strong in Java, Spring Boot, microservices patterns.
  - Hands-on Kafka development—streams, partitions, consumer groups. - Knowledge of distributed systems architecture.
  - Familiarity with Docker, cloud-native packaging.
  - Experience in REST APIs, schema evolution, and contracts.
  - Understanding of observability (logs, metrics, traces).
  - Good debugging and performance optimization skills.

Requirements:

• Strong experience with Java, Spring (Boot, Security, Data), and Hibernate
• Microservices architecture development experience
• Solid knowledge of:
  • AWS (EC2, RDS, SNS, SQS, Lambda)
    Kubernetes, Docker
  • PostgreSQL
  • Elasticsearch or OpenSearch
• Conversational English for team communication and documentation
• Ability to work from an office in the EU

Nice to have:

• Experience in backend development for mobile applications

We offer:

• Competitive market-level salary 

• International team and a chance to work on a world-class product

• Compensation for lunches

• Opportunities for professional growth and development

Are you ready to take ownership of mission-critical backend systems in a high-load, transaction-heavy environment? 

We are looking for a Senior Java Developer to join our Payments Domain team in Warsaw.

This is a hybrid role with 3 days per week in the office, giving you the perfect balance between collaboration and flexibility. 

At Sigma Software, we value engineering excellence, multicultural teamwork, and delivering secure, high-performance solutions.

Why join us? You’ll work on a platform processing millions of transactions daily, contribute to architectural decisions, and be part of a company where innovation and ownership are encouraged.
 

Customer

Our customer is a well-established international company in the iGaming industry, known for its engineering-driven culture and multicultural team distributed across multiple countries. Operating multiple brands across various markets, the company delivers secure, high-performance digital platforms recognized for reliability and scalability.
 

Project

You will be part of the Payments Domain team, responsible for developing and maintaining a large-scale payments platform built on modern microservices architecture. The platform processes millions of secure transactions daily, supporting multiple brands and geographies. The work focuses on scalability, reliability, and performance in a high-load environment, covering everything from integration with payment providers to transaction monitoring and compliance.

Requirements:

• 5+ years of commercial experience with Java and Spring Boot
• Strong experience with MySQL and Kafka
• Proven track record working with microservices architecture in high-traffic, high-load systems
• Experience developing high-performance backend solutions for transaction-heavy platforms
• Ownership mindset with the ability to deliver services end-to-end
• Excellent communication skills in English (C1 level), both written and verbal
• Experience with Kotlin
   

Responsibilities:

• Design, develop, and maintain backend services for the payments platform using Java and Spring Boot
• Ensure high availability, scalability, and performance of transaction processing systems
• Collaborate with cross-functional teams to define technical requirements and deliver solutions end-to-end
• Implement integrations with payment service providers and internal systems
• Participate in architectural discussions and contribute to system evolution in a microservices environment
• Monitor, troubleshoot, and optimize services in production
• Ensure compliance with security, regulatory, and operational standards
• Drive continuous improvement in code quality, testing, and deployment practices