5 days Onsite 

Must-Have Qualifications

• 5+ years professional C++ (C++11/14/17), Standard Template Library (STL), Resource Acquisition Is Initialization (RAII), templates, exceptions; strong debugging and performance tuning.
• POS domain expertise with CMA/NCR OmniPOS (or similar): configuration, extension, APIs, scripting/plug-ins, troubleshooting.
• Business flow understanding: transaction lifecycle, promotions/discount engines, tax, returns/exchanges, tender orchestration, reconciliation.
• Loyalty experience: identification (barcode, phone, card, token), points accrual/redemption, earn/burn rules, stackability with offers, breakage handling, edge cases (split tenders, offline accrual).
• Concurrency & performance: threads, async I/O, synchronization primitives; profiling tools (e.g., valgrind, perf).
• OS & tooling: Windows and/or Linux, build systems (CMake/Make/MSBuild), Bitbucket; debuggers (Visual Studio, gdb/lldb).
• Device integration: OPOS/JPOS, serial/USB/network peripherals; driver SDKs and state recovery strategies.
• Testing: unit/integration tests (GoogleTest/Catch2), mocks/stubs, automated builds.

Nice-to-Have Skills

• Payments: EMV/contactless, PSP integrations, tokenization, partial auth and fallback logic, settlement/reconciliation workflows.
• Retail back office: price/PLU updates, item master sync, promotions distribution, store-to-HQ messaging, inventory adjustments.
• Distributed/edge systems: store servers, offline-first patterns, eventual consistency, conflict resolution.
• Adjacent languages: Python, C#/.NET, Java for tooling/bridges.
• Observability: structured logging, metrics, tracing (OpenTelemetry), log aggregation (Splunk/ELK).
• Security: static analysis (clang-tidy/sonar), supply chain hygiene, secrets management.
• DevOps: Docker, CI/CD (Azure DevOps/GitHub Actions), artifact management.
• UI experience: Win32/MFC/Qt or web-based POS front ends integrated with C++ services.