Jobs Java

Who we are:

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

About the Product: 
Over the past few years Coro has received $175M in funding and is one of the fastest growing Cybersecurity companies in the world. The funding is primarily being used to enhance the Coro Cybersecurity SaaS platform and for additional headcount growth, as Coro continues to expand globally.   

Coro started in Tel-Aviv, Israel and is also headquartered in Chicago, IL with additional offices in New York, London, and remotely across the globe. As a global organization, Coro gives you the ability to work with people and teammates from around the world. 

Coro’s AI enabled Modular Cybersecurity Platform is the only one in the industry specifically designed to provide Mid-Market customers with scalable and affordable “enterprise grade” protection for all of their priority threat vectors. 

About the Role: 
This is a hands-on leadership role for a Backend Team Lead who will guide a team of backend engineers while staying directly involved in coding, architecture, and delivery. You will work on core backend systems behind Coro’s cybersecurity platform, building and scaling high-load services that process large volumes of security and telemetry data in real time.

These systems are responsible for collecting, processing, and analyzing data from multiple sources, including endpoints, cloud environments, and product integrations. They support critical product capabilities such as threat detection, security analytics, anomaly identification, and automated response workflows, making this a mission-critical leadership role at the core of Coro’s product.

If you are looking for a role where you can combine leadership with technical ownership, shape team culture, and build highly scalable backend services for a fast-growing global cybersecurity platform, this is the role for you

Key Responsibilities: 

• Lead a team of highly skilled and passionate developers
• Partner with the Product Manager to build the road-map for the team
• Understand the team objectives and key results and make sure that the team are on the path to achieving them
• Participate in making decisions on the architecture and technologies
• Conduct the team ceremonies: Daily stand-ups, sprint planning and retro meetings
• Help create and enforce strong engineering standards, code quality, and best Engineering practices
• Take an active part in the implementation (hands-on) of the team's various services and features

• Help your team members grow by mentoring them, building their growth plan with them and enable them opportunities to implement it

   

Required Competence and Skills:

• 6+ years of backend/server-side development with Java
• 2+ years of proven experience leading an engineering team 
• Strong hands-on experience with Spring Framework and MongoDB
• Deep understanding of multithreading and concurrency
• Solid knowledge of OOP concepts and design patterns
• Proven experience with microservices architecture
• Experience working with high-load backend systems
• Proficiency in cloud-native environments (preferably AWS)

Nice to have:

• Experience with Redis and RabbitMQ
• Experience with Elasticsearch/OpenSearch 
• Familiarity with Docker / Kubernetes
• Experience in Cybersecurity domain 

Why Us?

We provide 20 days of vacation leave per calendar year (plus official national holidays of a country you are based in).

We provide full accounting and legal support in all countries we operate.

We utilize a fully remote work model with a powerful workstation and co-working space in case you need it.

We offer a highly competitive package with yearly performance and compensation reviews.

Who we are:

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

About the Product: 
Over the past few years Coro has received $175M in funding and is one of the fastest growing Cybersecurity companies in the world. The funding is primarily being used to enhance the Coro Cybersecurity SaaS platform and for additional headcount growth, as Coro continues to expand globally.   

Coro started in Tel-Aviv, Israel and is also headquartered in Chicago, IL with additional offices in New York, London, and remotely across the globe. As a global organization, Coro gives you the ability to work with people and teammates from around the world. 

Coro’s AI enabled Modular Cybersecurity Platform is the only one in the industry specifically designed to provide Mid-Market customers with scalable and affordable “enterprise grade” protection for all of their priority threat vectors. 

About the Role: 

This is a hands-on leadership role for a Backend Team Lead who will guide a team of backend engineers while staying directly involved in coding, architecture, and delivery. You will work on core backend systems behind Coro’s cybersecurity platform, building and scaling high-load services that process large volumes of security and telemetry data in real time.

These systems are responsible for collecting, processing, and analyzing data from multiple sources, including endpoints, cloud environments, and product integrations. They support critical product capabilities such as threat detection, security analytics, anomaly identification, and automated response workflows, making this a mission-critical leadership role at the core of Coro’s product.

If you are looking for a role where you can combine leadership with technical ownership, shape team culture, and build highly scalable backend services for a fast-growing global cybersecurity platform, this is the role for you

Key Responsibilities: 

• Lead a team of highly skilled and passionate developers
• Partner with the Product Manager to build the road-map for the team
• Understand the team objectives and key results and make sure that the team are on the path to achieving them
• Participate in making decisions on the architecture and technologies
• Conduct the team ceremonies: Daily stand-ups, sprint planning and retro meetings
• Help create and enforce strong engineering standards, code quality, and best Engineering practices
• Take an active part in the implementation (hands-on) of the team's various services and features

• Help your team members grow by mentoring them, building their growth plan with them and enable them opportunities to implement it.

   

Required Competence and Skills:

• 6+ years of backend/server-side development with Java
• 2+ years of proven experience leading an engineering team 
• Strong hands-on experience with Spring Framework and MongoDB
• Deep understanding of multithreading and concurrency
• Solid knowledge of OOP concepts and design patterns
• Proven experience with microservices architecture
• Experience working with high-load backend systems
• Proficiency in cloud-native environments (preferably AWS)

Nice to have:

• Experience with Redis and RabbitMQ
• Experience with Elasticsearch/OpenSearch 
• Familiarity with Docker / Kubernetes
• Experience in Cybersecurity domain 

Why Us?

- We provide 20 days of vacation leave per calendar year (plus official national holidays of a country you are based in).

- We provide full accounting and legal support in all countries we operate.

- We utilize a fully remote work model with a powerful workstation and co-working space in case you need it.

- We offer a highly competitive package with yearly performance and compensation reviews.

Our client is a leading European online car marketplace with over 30 million monthly users and a presence in 18 countries. As a Senior Java Engineer, you will play a pivotal role in shaping the future of online car markets, contributing to the platform’s scalability, reliability, and overall user experience for millions of car buyers and sellers across Europe.
 

Responsibilities:

• Design, implement, and maintain scalable backend services in Java.
• Model complex business domains using strong type systems.
• Build and manage event-driven, distributed systems with high throughput.
• Contribute to architectural decisions regarding concurrency, streaming, and data consistency.
• Write clean, testable, and maintainable code following best practices.
• Improve CI/CD pipelines, system observability, and reliability.
• Collaborate closely with product, platform, and engineering teams to deliver high-quality solutions.
   

Requirements:

• 5+ years of backend development experience in Java.
• Strong knowledge of Spring Boot.
• Hands-on experience with event-driven architectures, preferably Kafka.
• Practical experience with the Typelevel ecosystem (Cats, Cats Effect, FS2, Http4s).
• Deep understanding of:
  • Effect systems (Cats Effect);
  • Functional programming principles;
  • Type classes and higher-kinded types;
  • Pure vs impure boundaries.
• Experience building distributed systems.
• Strong understanding of concurrency and asynchronous programming.
• Upper-Intermediate English or higher for technical communication.
   

Nice to Have:

• Experience with Scala 3.
• Experience with PHP.
• Knowledge of tagless-final patterns.
• Background in fintech or high-integrity domains.
• Contributions to open source projects.
   

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

System Department робить пристрої розумними, перетворюючи їх на повноцінний IoT. Вони створили й розвивають OS Malevich (модульна RTOS для різних апаратних платформ) і хмарний сервіс Ajax Cloud (Java 20 / Kotlin, AWS, Akka, NATS, Kafka, Mongo, MySQL). Для керування, обслуговування та моніторингу системи користувачами, інсталяторами й інженерами охоронних компаній розроблені додатки для iOS (Objective-C, Swift), Android (Java, Kotlin), Windows/macOS (Python / C++, QT, QML)

Responsibilities:

Core Development

• Design and implement core backend services and data pipelines
• Write clean, readable, and maintainable code
• Develop services for the B2B product line

Architecture & Documentation

• Participate in designing and improving system architecture
• Document architectural decisions and operational processes to support reliable deployment and service operations

Quality Assurance

• Ensure proper test coverage (unit and integration tests)
• Optimize performance and cost efficiency within owned areas
• Follow and promote best practices in software design and development

Operations & Monitoring

• Set up and maintain alerting, dashboards, and runbooks for production services
• Debug production issues, analyze complex cases, and conduct investigations

Collaboration & Culture

• Work in an engineering culture focused on testing, Continuous Delivery, and DevOps
• Collaborate with team members and other engineering teams to deliver features aligned with business needs

Requirements:

Required Experience

• 3+ years of professional backend development in Java (enterprise environment)
• Hands-on experience with Kotlin
• Strong understanding and practical experience with Java Concurrency

Architecture & Design

• Understanding of SOA, microservices, and event-driven architecture
• Practical experience with AWS and cloud development principles
• Experience building scalable, high-availability systems

Technologies & Tools

Required:

• Experience with NoSQL databases
• Experience with message brokers
• Familiarity with enterprise-grade stack (messaging systems, in-memory storage, key-value databases)
• Docker and Kubernetes
• Git, Gradle, Jenkins

Nice to Have:

• Redis, Netty, Akka
• gRPC, Project Reactor
• NATS, Kafka
• MongoDB

Testing & Quality

• Strong knowledge of unit testing
• Understanding of automated testing practices

What You Will Get

• Opportunity to propose and implement your own ideas with a real impact on the product and production
• Work in a highly motivated team with a zero-bullshit culture
• Competitive salary
• Health insurance
• Corporate English classes
• Compensation for professional development and learning
• Opportunity to participate in beta testing of Ajax security systems — get early access to and test new devices before their official release

We are looking for a Backend Developer (Java / Spring Boot) to join a client project in an outstaff format. In this role, you will focus on the implementation and further development of backend services, business logic, REST APIs, and microservices within an Azure-based environment. The ideal candidate has strong hands-on experience with Java / Spring Boot, PostgreSQL, Azure services, and backend architecture best practices.

Responsibilities:

• develop and further improve backend services and business logic using Java / Spring Boot
• implement REST APIs and microservices
• integrate internal and external systems
• work with Azure Database for PostgreSQL: schema design, queries, migrations, and performance optimization
• handle errors and exceptions, implement validations, logging, and monitoring hooks
• create unit and integration tests
• contribute to authentication / authorization and role-based access implementation
• refactor legacy logic and help reduce technical debt
• participate in architectural discussions, API design, and data model improvements

• support performance analysis, scaling, and backend-level cost optimization

   

Requirements:

• solid experience with Java and Spring Boot
• experience building REST APIs and microservices
• experience with Azure Container Apps
• strong knowledge of PostgreSQL: schema design, queries, migrations, and optimization
• experience with Azure Identity Management (AD B2C / Entra) or similar solutions
• experience with Azure DevOps (Repos, Pipelines)
• understanding of error handling, logging, and validation best practices
• experience writing unit and integration tests
• understanding of backend architecture, service boundaries, and development best practices
• ability to write clean, maintainable code
• English B2+ level 

We're seeking a Software Java Engineer with 5+ years of experience to help build and scale the backend services that power our content discovery, licensing, and delivery platforms across all of our content libraries. You'll join a team that's passionate about clean architecture, performance, and solving complex challenges at scale. If you thrive in a collaborative environment and love building robust APIs, data-driven systems, and data modeling we'd love to hear from you.

What You'll Do:

• Design, implement, and maintain backend services using Java, Spring Boot, and the broader Spring ecosystem.
• Build and evolve RESTful APIs that power content metadata, search, recommendation, and licensing workflows.
• Work with Kafka to build event-driven and real-time processing systems.
• Use SQL and work with relational databases to support structured content metadata.
• Partner with data and analytics teams to model data in data warehouses, supporting reporting and analytics use cases.
• Build and maintain DBT models to transform raw data into clean, usable datasets.
• Leverage the AWS ecosystem for service deployment, data storage, and pipeline orchestration.
• Contribute to technical discussions, system design, and code reviews.

Requirements:

• 5+ years of professional backend development experience.
• Strong proficiency in Java, with experience using Spring Boot and Spring Framework.
• Experience designing and consuming REST APIs.
• Familiarity with Kafka or other message streaming platforms.
• Solid understanding of relational databases and writing optimized SQL.
• Comfortable working with GraphQL.
• Exposure to Python.
• A collaborative mindset with strong communication skills.
• A passion for clean code, scalable systems, and continuous learning.

Nice-to-Have:

• Practical experience working with data warehouses and DBT for data transformation and modeling.
• Hands-on experience working with the AWS ecosystem (especially Aurora/Dynamo DB).
• Experience working with Node.js and/or Typescript.
• Knowledge of containerization and orchestration (Docker, Kubernetes).
• Experience with Databricks/Snowflake.
• Background in building systems for search, metadata enrichment, or digital asset management.

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

Job Description

We are seeking a Technical Lead to drive the design and development of the new OneAPI backend platform, a scalable API infrastructure running on cloud-native architecture (AWS & GCP). The Technical Lead will guide a small team of engineers, provide hands-on coding expertise, and ensure delivery excellence with a DevOps-first mindset.

• 10+ years of backend engineering experience with strong expertise in Java & Spring Boot.
• Proven experience building platform-level APIs and distributed systems.
• Deep knowledge of cloud platforms (AWS and/or GCP) and cloud-native architectures.
• Strong Kubernetes (K8s) experience for container orchestration.
• DevOps mindset: CI/CD pipelines, monitoring, observability, automation.
• Experience leading small, versatile teams and collaborating across disciplines.
• Experience working in a team responsible for products quality
• Strong problem-solving and communication skills.

Job Responsibilities

• Lead architecture and technical design for the OneAPI backend platform.
• Drive best practices in coding, testing, CI/CD, and DevOps culture.
• Collaborate with stakeholders to define API standards, integration patterns, and platform roadmap.
• Provide technical mentorship and guidance to the engineering team.
• Ensure solutions are secure, scalable, and optimized for performance.
• Ensure quality of develope software
• Participate hands-on in development, especially in critical/complex components.

Department/Project Description

Our client is a global leader in cloud security, enabling organizations to securely transform their networks and applications for a mobile and cloud-first world. Through its Zero Trust Exchange™ platform, it provides fast, secure, and seamless access to applications, regardless of device, location, or network. Trusted by thousands of enterprises, their products help reduce risk, lower IT costs, and deliver a better user experience by replacing traditional on-premises security with a modern cloud-delivered approach.

Intempt.com is an agentic growth platform — CDP, CRM, experimentation, personalization, recommendations, journeys, analytics, and AI agents in one platform. One event-centric data model powers everything. Small team, high output. You own systems, not tickets.

What you'll build

Event pipeline. Kafka ingestion → Flink processing → validated, deduplicated, identity-stitched events available to every downstream system in near real-time. Millions of events/day.

Identity resolution. Anonymous-to-known merging, cross-device stitching, account grouping, attribute reconciliation. The backbone of our CDP — if profiles are wrong, everything downstream is wrong.

Data layer across four engines. Postgres (profiles, accounts, consent, config). Redis (session state, real-time segments, feature flags). Neo4j (account hierarchies, affinity graphs). ClickHouse (funnels, retention, experiment results, dashboards).

LLM infrastructure. Our AI agents (Qualification, Lifecycle, Research, + orchestrator Blu) hit inference APIs at scale. You build the machinery — prompt routing, model selection, token budgets, response caching, failover — not the prompts.

Public APIs. Track, identify, consent, choose, recommendations feed. You own correctness, performance, and evolution.

Typical week

• Ship a Flink job computing real-time experiment metrics → ClickHouse
• Debug a profile merge edge case where alias() fired after events were already attributed
• Take a ClickHouse retention query from 8s to 200ms
• Wire a new Shopify/HubSpot attribute path into unified profiles

• Instrument an LLM call path with token tracking, latency monitoring, automatic fallback

   

What you need

• Java — deep, production-level. JVM tuning, GC behavior, concurrency, data structure choices at 50k events/sec.
• Postgres — migrations, indexing, connection pooling, replication. Not just SELECT.
• Redis — beyond caching. Pub/sub, sorted sets.
• Kafka — topic design, consumer groups, backpressure, exactly-once semantics.
• Flink (strong plus) — stateful processing, windowing, checkpointing. Spark Streaming / Kafka Streams also counts.
• ClickHouse or Neo4j — working knowledge of at least one. Ideally both.

• LLM integration — inference APIs in production. Token limits, latency, retries, cost control.

   

Who you are

• 3–5 years building backend systems. Mid-level operating like senior.
• You own problems end-to-end: root cause → fix → deploy → monitor.
• You learn fast. You'll hit unfamiliar systems. Read docs, build mental model, ship.

• You write code others can maintain and communicate in writing — design docs, PR descriptions, postmortems.

   

What we offer

• Work alongside some of the best backend and full-stack engineers you'll ever meet
• Work directly with the founder — a UC Berkeley computer scientist who's in the code daily
• Autonomy — context, not micromanagement
• A codebase young enough to be shaped by you

Language Requirements

• At least an intermediate level of spoken and written English, enabling clear and effective communication with team members and stakeholders.

   

Hiring Process

1. 15-minute Founder Interview

2. 45–minute Engineering Interview

    

   • Architecture reasoning
   • Code/system walkthroughs
   • Scaling and failure-mode thinking

How to apply

Please email hey at intempt.com  Subject: "Backend Platform Engineer" Resume + one or two things you've built that you're proud of. No template. Just what's real.

Equal Opportunity

Intempt Technologies is an equal opportunity employer. We value diversity and do not discriminate based on race, religion, color, national origin, gender, sexual orientation, age, marital status, veteran status, or disability status.

Project Description:

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:

6+ years of hands-on Java development experience

Strong Java Core knowledge

Experience with desktop development frameworks: Swing, SWT, or Eclipse RCP

Proven experience designing and building complex systems end-to-end, not just maintaining or extending existing ones

Practical understanding of multithreaded programming: ability to implement concurrency in code directly, not only through third-party libraries

Solid knowledge of design patterns and software architecture principles

Ability to clearly articulate past projects, personal responsibilities, and concrete individual contributions

Experience working in non-microservices, non-cloud-native development environments (desktop, embedded, or domain-specific platforms)

Stable career trajectory, no fragmented job history with short tenures

Nice-to-Have Skills Description:

C++ development skills

Practical experience with the Eclipse RCP framework

OSGi knowledge

Oil & Gas domain experience

Languages:

English: B2 Upper Intermediate

• Project Description:

  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:

  6+ years of hands-on Java development experience
  Strong Java Core knowledge
  Experience with desktop development frameworks: Swing, SWT, or Eclipse RCP
  Proven experience designing and building complex systems end-to-end, not just maintaining or extending existing ones
  Practical understanding of multithreaded programming: ability to implement concurrency in code directly, not only through third-party libraries
  Solid knowledge of design patterns and software architecture principles
  Ability to clearly articulate past projects, personal responsibilities, and concrete individual contributions
  Experience working in non-microservices, non-cloud-native development environments (desktop, embedded, or domain-specific platforms)
  Stable career trajectory, no fragmented job history with short tenures

Intetics Inc., a global technology company providing custom software application development, distributed professional teams, software product quality assessment, and “all-things-digital” solutions, is seeking a highly skilled and experienced Senior Java Engineer to join our dynamic team on a full-time basis.

Project Overview:
The project focuses on developing and maintaining high-load, mission-critical banking systems that require high availability, performance, and reliability. The engineer will be involved in the full software development lifecycle and will work on building high-volume, low-latency applications for critical systems.

Key Responsibilities:
Design and develop high-volume, low-latency applications for mission-critical systems
Participate in all phases of the software development lifecycle
Write well-designed, testable, and efficient code
Ensure solutions comply with architectural and technical specifications
Prepare and produce releases of software components
Support continuous improvement by researching and proposing new technologies and approaches

Required Experience & Skills
5+ years of professional software development experience
Strong experience with Java / Java EE development
Experience with Spring Framework
Strong knowledge of relational databases, SQL, and ORM technologies (JPA2, Hibernate)
Solid understanding of object-oriented design and design patterns
Deep understanding of Java/JEE internals (classloading, memory management, transaction management, etc.)
Experience with web frameworks such as JSF, Wicket, GWT, or Spring MVC
Experience with Test-Driven Development (TDD)
Experience working with high-load systems

Ability to visit the client’s office in Tbilisi, Georgia
Bachelor’s or Master’s degree in Computer Science, Engineering, or a related field

A global marketplace for savings and investments, providing users with seamless access to high-yield savings accounts and investment options from over 400 partner banks worldwide. The platform removes geographic barriers while ensuring transparency, convenience, and competitive rates. For banks, it delivers cost-efficient deposit funding and innovative Banking-as-a-Service solutions. The team is responsible for the integration of transaction accounts, hosted via our servicing banks, into the Raisin platform. They ensure smooth funding across all products, correctly routing incoming and outgoing payments to their intended destinations. The team consists of 10 members working collaboratively in a cross-functional setup.

Responsibilities:

• Deliver core services and high-quality solutions for a large-scale online platform and its banking systems.
•  Integrate externally developed components into existing applications.
• Define standards, share best practices, and contribute to continuous learning within the team.
• Perform software engineering tasks with a strong focus on quality and support teammates in maintaining the same standards.
• Conduct thorough code reviews, covering best practices, business rules, performance, security, and impact on other features/projects, always providing constructive and respectful feedback.
• Collaborate within the team to negotiate and document software development standards and practices.
• Research and propose multiple technical solutions whenever possible.
• Take end-to-end ownership of project delivery within the team.
• Maintain and manage technical documentation and address technical debt proactively.
• Participate in the hiring process through tech-fit interviews and technical challenge evaluations.

Requirements:

• 6+ years of overall software development experience.
• Minimum 5 years of experience with Java and Spring Boot.
• Strong understanding and hands-on application of design patterns.
• Practical experience with testing practices (unit, integration) using tools such as JUnit, Mockito, TestContainers.
• 4+ years of experience with AWS Services, Kubernetes, event-driven architectures (Kafka or ActiveMQ), Spring Boot, SQL, and NoSQL.
• Excellent communication skills with the ability to articulate challenges and solutions clearly.
• Proven team player who collaborates effectively and supports shared goals.
• Strong critical thinking and problem-solving skills, with the ability to analyze production issues and design robust solutions (highly desirable).
• Proactive in supporting teammates and driving technical improvements (strongly preferred).
• High responsibility when working with payments, as this is a critical, core functionality for the company.

The product company is looking for Java Developer!

An international product company — a successful market leader, a live-streaming platform with 450+ million registered users. The B2C mobile platform enables millions of talented people worldwide to connect with their fans and monetize their skills.

Founded in 2018 in the USA, with more than 350 employees globally. They offer: stock options, medical insurance (100% for employees and 75% for family members), office lunches, parking, and a multisport card.

Technology stack: Java 17–21, Spring Boot, Kafka, Kubernetes, Aerospike, Redis, GCP.

Requirements: experience with Java, Spring, Kafka, microservices, and Cloud platforms.

Onicore is a FinTech company specializing in developing products for cryptocurrency operations. We strive to make crypto convenient and understandable for everyone.
 
And now we are looking for a talented and experienced Java Team Lead to join our team. If you’re passionate about working with the latest technologies, contributing to exciting product developments, and collaborating with an awesome team, we want to hear from you!
 
Your Key Duties:

• Design, develop, and maintain high-performance, scalable Java-based applications in the FinTech domain.
• Implement and optimize multithreaded and concurrent solutions, ensuring thread safety and system reliability.
• Build and maintain microservices using the Spring ecosystem.
• Ensure database efficiency, including query optimization, proper indexing, and transaction handling.
• Evaluate and improve application performance, conduct profiling sessions, and resolve bottlenecks.
• Design and implement synchronous and asynchronous integrations with internal and external systems.
• Participate in architectural discussions, propose improvements, and drive technical initiatives.
• Collaborate closely with product managers, architects, and QA engineers to deliver business-critical solutions.
• Write clean, maintainable, and well-tested code following best practices.
   

Your Skills:

• 5+ years of professional experience in Java development.
• Strong expertise in Java 17+ (knowledge of modern language features, streams, lambdas, functional programming concepts).
• Deep understanding of core Java:
• Collections Framework, Generics, Streams, Functional Interfaces
• Concurrency utilities (Executors, CompletableFuture, Fork/Join, Locks, Atomics, etc.)
• Proven experience with the Spring ecosystem: Spring Boot, Spring Data (JPA/Hibernate), Spring Security, Spring Cloud (microservices).
• Solid understanding of databases (SQL and/or NoSQL), including:
• Transactions, isolation levels, and locking mechanisms
• Query optimization and indexing strategies
• Hands-on experience with multithreading and concurrency, including race conditions, deadlocks, synchronization, and strategies to avoid them.
• Proficiency in synchronous and asynchronous communication: REST, messaging systems (Kafka, RabbitMQ, etc.), event-driven architectures.
• Experience working on FinTech or financial services projects.
• Strong focus on performance evaluation, scalability, and reliability.
• Strong problem-solving skills, ability to work independently, take initiative, and drive solutions proactively.
• Self-driven and responsible, capable of working with minimal supervision.
• Proactive, solution-oriented mindset.
• Team player with a collaborative attitude.
   

Nice to have:

• Experience with Kubernetes, Docker, and cloud-native environments.
• Experience with application profiling and performance tuning:
• Tools such as VisualVM, JFR (Java Flight Recorder), JMC (Java Mission Control)
• Identifying and resolving performance bottlenecks
• Analyzing complexity of SQL queries and optimizing execution plans
• Familiarity with CI/CD pipelines and DevOps practices.
• Knowledge of distributed systems, event sourcing, or CQRS.
   

What’s on us:

— Competitive salary and benefits package.

— Opportunities for professional development and career growth.

— Health insurance.

— Remote work with the possibility to visit our office in Kyiv.

— Space to share your ideas and bring them to life.

Is this all about you? Send us your CV!

Ajax Systems is a full-cycle company working from idea generation and R&D to mass production and sales. We create security solutions for residential and commercial properties, with a portfolio of 280+ devices across intrusion protection, video surveillance, fire safety, and automation. The whole team is in one office in Lviv, all technical and product decisions are made locally.

We’re looking for an Java Developer to join us and continue the evolution of a product that we love: someone who takes pride in their work to ensure that user experience and development quality are superb. You will be able to develop the apps in the best hardware company of Ukraine with around 300M active users around the world. Moreover, very soon you will have a chance to start several new products from scratch.

Required skills:

• 5+ years of commercial experience in backend development with Java in an enterprise environment;
• Strong understanding of Java Concurrency and hands-on experience with concurrent programming in production systems;
• Solid understanding of SOA, microservices, and event-driven architecture;
• Practical experience with cloud computing platforms;
• Experience building and supporting high-load, scalable, and highly available systems;
• Hands-on experience with messaging brokers;
• Strong understanding of modern backend infrastructure, NoSQL, key-value databases, and in-memory storage solutions;
• Practical experience with Docker or Kubernetes;
• Experience with Git, Gradle or othet CI/CD tools;
• Strong knowledge of unit testing and automated testing approaches.

Would be a plus:

• Experience with some of technologies: Redis, Netty, Akka, NATS, AWS, MQTT, Kafka, MongoDB, gRPC.
• Practical experience with Kotlin.

What you will do:

• Design and develop core backend services and data pipelines for the product line;
• Build clean, maintainable, and production-ready code with a strong focus on quality;
• Contribute to backend architecture, drive technical decisions, and document solutions for reliable deployment and operations;
• Ensure proper test coverage with unit and integration tests;
• Take ownership of performance, scalability, and cost efficiency within your domain;
• Maintain production reliability through monitoring, alerting, dashboards, and runbooks;
• Investigate and resolve production issues, including deep-dive analysis of complex cases;
• Work in a strong engineering culture with testing, continuous delivery, and DevOps practices;
• Collaborate closely with product and engineering teams to deliver new features and improve existing services.

Why this role is interesting:

• Opportunity to work on high-load backend systems and distributed architecture;
• Real impact on core product development and architectural decisions;
• Modern technology stack and engineering-driven environment;
• Close collaboration with experienced engineers in a culture that values quality, ownership, and technical excellence;
• Challenging tasks where performance, reliability, and scalability truly matter.

We offer:

• The opportunity to share and implement your own ideas that could impact products and production;
• Work with a motivated team and an environment with a zero-bullshit culture;
• Competitive salary;
• Medical insurance;
• Corporate English classes;
• Compensation for professional training;
• The chance to take part in beta testing of Ajax security systems — receive and test new devices before their release.

Ajax Systems is a Ukrainian success story, a place of incredible strength and energy.
Join us in making Made in Ukraine 🇺🇦 synonymous with reliability.