Payment flow understanding
Card transactions, acquiring, money transfers, chargebacks, refunds, reversals, fraud monitoring and 3DS/MPI verification.
Payment systems QA / REST API / transaction diagnostics
Manual QA Engineer who tests the business path behind every transaction.
I help teams verify payment flows, backend services, API contracts and data consistency across logs, databases and product behavior.
- Domain
- Payments, e-commerce, banking
- Core stack
- Postman, Jira, SQL, logs
- Testing scope
- API, E2E, regression, exploratory
QA Control Room
Release readiness
API checks
98%
contract + business validation
Risk focus
3DS
auth, reversal, refund
Defect path
API -> logs -> DB
root cause oriented
POST /payments/authorize 201 Created
ASSERT amount, currency, merchantId, authCode
TRACE transaction_id matched in service logs
SQL status = AUTHORIZED, risk_score = LOW
What I bring to a QA team
Manual testing with technical diagnosis, not just screen checking.
API-first testing
REST API validation in Postman: request and response data, HTTP statuses, authorization, negative paths and regression scenarios.
Data-backed investigation
Diagnostics across API, application logs and PostgreSQL to confirm whether product behavior matches business rules.
Production-aware mindset
Second Line Support background helps me read incidents, communicate with technical and business teams, and protect critical workflows.
Career trajectory
From technical support and banking systems to focused QA engineering.
Manual QA Engineer / Fenige S.A.
Manual testing of Java/Spring backend systems and Angular web applications in payment and transaction processes.
Second Line Support Engineer / Fenige S.A.
Technical analysis of payment systems, production and test environments, incidents, logs, API data and business inconsistencies.
IT and user support / PKO Bank Polski
Technical incident handling, access issues, banking application support and collaboration with IT teams and vendors.
Portfolio concept
Case studies built around real QA thinking and safe synthetic data.
Case 01
High business impact
Payment authorization regression
API and backend checks for amount, currency, merchant configuration, authentication result and final transaction state.
- Positive and negative Postman scenarios
- Database status verification
- Log correlation by transaction identifier
Case 02
Risk based
Refund and reversal validation
Scenario coverage for partial refund, failed reversal, duplicate request prevention and correct customer-facing status.
- Boundary and duplicate request testing
- Business rule checks
- Jira-ready defect evidence
Case 03
Technical diagnosis
Async status mismatch
Microservice and RabbitMQ-oriented analysis when frontend state, API response and database record do not agree.
- API -> logs -> DB investigation
- Async event consistency check
- Root cause hypothesis for developers
Interactive recruiter endpoint
Send a GET request and receive my QA profile as JSON.
A lightweight Postman-style console built into the portfolio. It turns the CV into structured, testable information.
Recruiter and QA Lead evidence
Selected work samples to add from your materials.
Synthetic sample
Refund status remains PENDING after successful provider confirmation
- Severity
- High
- Environment
- Test / API v2 / merchant sandbox
- Expected
- Refund status changes to COMPLETED and is visible in transaction history.
- Actual
- API returns provider success but database status remains PENDING.
Synthetic sample
Card authorization with 3DS challenge and successful capture
- Create authorization request with valid merchant, amount and currency.
- Complete 3DS challenge with approved authentication result.
- Verify HTTP status, response body and transaction identifier.
- Confirm final state in PostgreSQL and transaction dashboard.
Synthetic sample
Payment regression risk matrix
High impact / high probability
3DS timeout, duplicate refund, incorrect reversal status
High impact / low probability
Currency mismatch, acquiring configuration error
Medium impact
Frontend status delay, missing error translation
Synthetic sample
Postman validation checklist
pm.test("transaction is authorized", () => {
pm.response.to.have.status(201);
pm.expect(json.status).to.eql("AUTHORIZED");
pm.expect(json.amount).to.eql(pm.environment.get("amount"));
});Best private materials to sanitize and add next
One anonymized Jira defect, one Postman collection screenshot, one SQL/log investigation note, one regression checklist and one Confluence-style technical analysis. All with fake IDs, fake data and no client or production details.
Tools and methods
A practical stack for modern manual QA.
Manual testing
REST API
Postman
Swagger
SQL
PostgreSQL
Logs
Jira
Confluence
Metabase
pgAdmin
Jenkins / CI
Docker basics
Playwright basics
RabbitMQ basics
JSON / XML
Available for QA opportunities
Looking for a tester who understands both user impact and backend evidence?
I am ready to support teams building payment, transaction, banking and e-commerce products where quality depends on details hidden behind the UI.