Jobs Java, with public salary

We’re looking for a Senior Back End Engineer to join a B2B SaaS platform powering 1M+ live websites for tens of thousands of businesses worldwide.

The product combines a large-scale distributed architecture with AI-powered tools for content generation, SEO, translations, image descriptions, and automated website updates. You’ll work on core services where performance, concurrency, reliability, and scalability are critical.
 

What you’ll do:

Build and scale core backend services with Java and Spring Boot.

Design distributed microservices and high-performance APIs.

Solve complex multithreading, concurrency, and performance challenges.

Work with relational and NoSQL databases and optimize data models.

Own features end-to-end, from requirements to production.

Use AI-powered development tools to improve engineering productivity.

Influence architecture and infrastructure decisions and mentor other engineers.

What we’re looking for:

7+ years of backend development experience.

Strong Java, Spring, and Spring Boot skills.

Deep understanding of multithreading, concurrency, and performance optimization.

Experience with distributed systems, microservices, and API design.

Strong database and SQL skills.

Experience with unit and integration testing.

Ability to take ownership and work independently in a cross-functional team.

Fluent English.

Nice to have: TypeScript/React, Generative AI development tools, CI/CD, or experience in high-growth B2B SaaS.

🎰 Senior Java Engineer: Build the Wallet Behind Millions of Players

Adaptiq × a major online gaming operator

The challenge:

Picture a platform where millions of players hit "play" at the same moment, every action moves real money, and the answer must come back in under a second. Now picture building it from scratch.

That's the PAM (Player Account Management) platform: real-time financial transactions, strict regulation, zero tolerance for lost cents, and traffic spikes that would make most systems sweat. No legacy code to inherit. Just a blank page and hard problems.

Your role:

You'll design and build the core backend of the platform and own your features end-to-end: from RFC to production monitoring. You'll work side by side with Principal Engineers, with real autonomy and real influence on the architecture.

What you'll do:

• Build services in Java 17+ / Spring Boot for wallets, ledger, payments, bonuses, and account state
• Create REST APIs and Kafka-based event flows for frontends, ops tools, and partners
• Make correctness non-negotiable: idempotency, clear transaction boundaries, failure handling, solid testing
• Bake in compliance: KYC/AML, responsible gaming, audit trails
• Keep production healthy with metrics, tracing, alerts, and on-call
• Shape the platform through RFCs and code reviews, and mentor teammates
• Work with AI-assisted tools daily

• Help migrate live from the existing third-party platform (parity testing, data validation, cutover)

   

What you bring:

• 5+ years in backend engineering, with strong Java 17+ and Spring Boot
• Experience with high-integrity transactional systems: payments, wallets, billing, banking, e-commerce, or gaming
• Deep PostgreSQL (or similar) knowledge: schema design, ACID, locking, tuning
• Event-driven architecture experience (Kafka, RabbitMQ), including idempotency and retries
• Automated testing as a habit: unit, integration, contract
• Hands-on production experience with containers, CI/CD, observability, and incident troubleshooting
• Solid grasp of multi-threading and fault-tolerant design

• Good English and comfort working across time zones

   

Bonus points:

✦ iGaming, betting, or fintech background
✦ Kubernetes and AWS (VPC, IAM, EKS, auto-scaling)
✦ Compliance-driven development experience
✦ Agentic development workflows
 

If you want your code to handle real money, real scale, and real responsibility, let's talk.

Who we are:

Adaptiq is a technology hub focused on building, scaling, and supporting R&D teams for high-growth product companies across a broad range of industries.
 

About the Product:

Our client is a leading online gaming operator developing a new transactional platform for user account management. The platform is being built from scratch and will operate in a highly regulated, high-volume environment, supporting millions of concurrent users.

It will process real-time financial transactions and must provide high availability, sub-second response times, strong data integrity, security, and complete auditability. A major technical challenge is ensuring stable performance and reliability during peak events and significant traffic spikes.

The team is looking for strong engineering expertise to help architect and develop a scalable, high-performance, and resilient backend platform while meeting strict security, regulatory, and compliance standards.
 

About the Role:

As a Senior Java Engineer, you will build and design the core backend services of the PAM platform from the ground up. You will take end-to-end ownership of features, covering technical design, implementation, automated testing, production monitoring, and release.

You will collaborate closely with Principal Engineers on architecture and key technical decisions, contribute to RFCs, and deliver production-ready solutions. The role offers a high degree of autonomy and direct influence on the platform architecture, together with responsibility for reliability, performance, and correctness within a critical financial system.
 

Key Responsibilities:

• Design and develop backend services using Java 17+ and Spring Boot or a similar framework, covering wallet transactions, ledger entries, payment orchestration, bonus mechanics, and account state management.
• Build REST APIs and event-driven integrations with Kafka or similar technologies for player-facing applications, operational tools, and external partners.
• Maintain system correctness and reliability through idempotent operations, well-defined transaction boundaries, explicit failure handling, and comprehensive unit, integration, and contract testing.
• Incorporate regulatory requirements directly into the platform, including KYC/AML checks, responsible gaming controls, and audit trails.
• Ensure production readiness through metrics, structured logging, distributed tracing, alerting, and participation in on-call rotations.
• Participate in technical design discussions and RFCs, conduct code reviews, and support and mentor other engineers.
• Integrate AI-assisted development tools into the daily engineering workflow while following established platform standards for prompts and context.
• Support the live migration from the existing third-party platform, including parity testing, data validation, and cutover coordination.
   

Required Competence and Skills:

• 5+ years of backend engineering experience with strong hands-on expertise in Java 17+ and a modern framework such as Spring Boot.
• Proven experience designing, building, and operating high-integrity transactional systems in areas such as payments, wallets, billing, banking, e-commerce, or gaming.
• Strong knowledge of relational databases such as PostgreSQL, including schema design, ACID transactions, locking, and query/performance optimization.
• Experience working with event-driven architectures and messaging technologies such as Kafka, RabbitMQ, or similar, including idempotency and retry mechanisms.
• Strong automated testing practices, including unit, integration, and contract testing as part of the regular development lifecycle.
• Practical production experience with containers, CI/CD pipelines, monitoring and telemetry, as well as troubleshooting production incidents.
• Solid knowledge of multi-threading, system architecture, and fault-tolerant design patterns.
• Good written and spoken English and experience collaborating effectively across distributed, multi-time-zone teams.
   

Nice to Have:

• Experience in iGaming, sports betting, fintech, or another regulated domain with high transaction volumes.
• Hands-on exposure to Kubernetes and AWS technologies, including VPC, IAM, EKS, and auto-scaling.
• Experience building systems with compliance requirements such as KYC/AML, responsible gaming, and auditability.
• Practical experience using AI coding assistants and agentic development workflows.
• Polish and/or Spanish language skills.
   

Why Us:

We provide 20 days of paid vacation per calendar year, in addition to the official national holidays of the country where you are based.

We offer full accounting and legal support across all countries where we operate.

We follow a fully remote work model and provide a powerful workstation, as well as access to a co-working space whenever needed.