Kotlin/Java Developer, Merchant Response

Role Overview

• Developing new payment features and services;
• Processing and resolving requests from technical support and users as part of daily duties;
• Designing and implementing APIs (external and internal);
• Creating and maintaining processes in Camunda;
• Participating in the design and development of high-load system architectures;
• Supporting and enhancing existing solutions and services;
• Writing high-quality, test-covered code (unit tests, integration tests);
• Conducting code reviews;
• Optimizing system performance and database queries;
• Analyzing and resolving production incidents and bugs;
• Analyzing documentation from external providers, conducting quick checks, and defining epics and tasks based on Proof of Concept;
• Collaborating with the QA team to ensure the high quality of the delivered product;
• Maintaining technical documentation and writing technical specifications;
• Assisting in onboarding new developers and ensuring code quality;
• Definition and formation of technical epics — analyzing existing solutions, identifying opportunities to improve system architecture, performance, and reliability, preparing improvement proposals, and aligning them with the team lead and architect;
• Participation in the creation of business epics — analyzing requirements, assessing feasibility, and proposing alternative or optimized solutions based on technical expertise; collaborating with analysts and product managers to determine the best implementation approach;
• Preparing tasks based on approved epics, ensuring proper detailing and alignment with architectural and business requirements;
• Estimating task completion timelines, participating in sprint planning, and providing accurate technical time and effort estimates.

Requirements

• 3+ years of commercial development experience with Kotlin;
• Experience with the Spring Framework;
• Experience in developing payment solutions (billing, payment gateways, payment processors, exchanges);
• Practical experience integrating with external providers;
• Experience designing and optimizing relational databases (MySQL);
• Experience with NoSQL databases (Redis);
• Practical experience using AI-assisted coding tools (Claude, Codex, ChatGPT, Codeium, etc.) to improve speed and quality of development;
• Ability to critically review AI-generated code, ensuring production-ready quality and compliance with company standards;
• Knowledge of Event-Driven Architecture principles and experience working with distributed messaging systems (e.g., Apache Kafka);
• Excellent command of core software development and design principles, test-driven development (TDD), and CI/CD processes;
• Strong understanding of microservice architecture.
• Preferred Qualifications:
• Experience with Camunda (creating and supporting processes);
• Solid understanding of PCI DSS standards, ISO 27001, and other information security methodologies;
• Practical experience working with AWS;
• Experience with Jira and GitLab CI/CD.

Tech Stack

• Apache
• AWS
• Kafka
• Kotlin
• MySQL
• NoSQL
• Redis
• Spring

Benefits

• Full remote work.
• Competitive compensation with a service contract.
• Transparent performance reviews twice a year, with bonus opportunities and salary adjustments.
• An annual allowance that you can use for home office improvements, sports activities, equipment upgrades, and more—tailor it to what benefits you most.
• Investment in your development: paid language courses, access to various learning platforms, and a mindfulness benefit, including psychological support with 50% coverage.
• Career growth in a fast-scaling project with opportunities to influence technical decisions.
• A culture of recognition: our peer reward program celebrates contributions from across the team.