• Perform hands-on UI, API, backend, database, integration, and blockchain testing for wallet creation, deposits, withdrawals, payouts, fees, balances, mass payouts, and transaction-monitoring functionality across Bitcoin, Ethereum, TRON, ERC-20, and TRC-20 flows.
• Design and execute functional, regression, exploratory, integration, and release testing for complex financial and blockchain business logic; validate backend state and data directly in PostgreSQL and investigate cross-service defects.
• Analyse requirements, external-provider documentation, technical specifications, user stories, and acceptance criteria; identified business-logic defects in fee calculations before production release.
• Established the project test strategy, testing levels, scope estimation, release-quality gates, and release-readiness criteria; supported approximately one production release per month without critical or blocking defects in production within the tested scope.
• Combine hands-on testing with leadership of a 3-person QA team.

• Performed hands-on UI, API, backend, integration, regression, and blockchain testing across three B2B and B2C crypto-processing products with an approximate two-week release cadence.
• Planned test scope, estimated QA effort, assessed release risks, investigated defects, and maintained release-readiness visibility across several products and architectures.
• Established consistent QA workflows, structured test planning, Definition of Ready, Definition of Done, test documentation, and transparent reporting of completed scope, remaining work, and release risks.
• Improved planning, prioritisation, and QA workflows, increasing the average number of completed tasks per sprint from approximately 5 to 9 while maintaining production quality in the tested scope without confirmed critical incidents.
• Led QA specialists with up to 7 direct reports, including mentoring, onboarding, and work allocation.
• Supported an approximate two-week release cadence and maintained production quality in the tested scope without confirmed critical production incidents.

• Established the complete testing process for a new product from scratch, including testing approaches, test documentation, scope planning, effort estimation, and QA release-readiness assessment.
• Performed hands-on UI, API, backend, PostgreSQL, functional, regression, and release testing; maintained test plans, test cases, checklists, defect reports, and test reports.
• Continuously analysed product behaviour and usability, worked with developers and stakeholders to reduce release risks, and prevented critical or blocking defects in the tested scope from reaching production.
• Worked with developers and project stakeholders to reduce release risks and prevented critical or blocking defects in the tested scope from reaching production.

• Performed UI, API, backend, database, functional, regression, exploratory, and production-readiness testing for a B2B payment system.
• Used exploratory testing to identify undocumented functionality and behaviour, providing product knowledge that supported migration from a monolithic architecture to microservices.
• Established structured test planning, progress tracking, risk assessment, and QA release-readiness ownership after product acquisition; maintained the tested scope without confirmed critical production incidents.

Executed regression testing for telecommunications and CRM systems, maintained test documentation, and documented results and defects.

• Performed manual testing of embedded systems and application software together with API and backend testing; developed test strategies, plans, schedules, test scenarios, and API testing scripts.
• Standardised certification and expert-review preparation, reducing readiness time from approximately 5 working days to 1-2 working days; improved defect investigation and reduced incident-resolution time from up to 5 days to approximately 2-3 days.
• Localised difficult-to-reproduce intermittent defects in two devices and coordinated testing with development, support, and technical-maintenance teams through product implementation and operation.

Earlier engineering and team-leadership experience; managed technical and organisational activities within a technology bureau.