Senior Business Analyst

N-iX is looking for a Senior Business Analyst for one of our clients.

Our client, an award-winning global tax services and software provider, is the largest Firm in the world dedicated exclusively to business taxes. With global headquarters in Dallas, Texas, the Firm provides an integrated suite of federal, state, local, and international tax services on a multijurisdictional basis, including tax recovery, consulting, advocacy, compliance, and technology services.

About Project: We are developing an API Engine for B2B SaaS platform that enables VAT compliance across multiple jurisdictions, ERP systems, and external tax authority APIs. The role focuses on transitioning complex system logic into a modern, integration-driven architecture while maintaining interoperability with existing core systems.

Responsibilities:

• Collaborate with Product, Engineering, and Architecture to elicit functional and non-functional requirements for the API Engine, identify implicit assumptions, edge cases, and dependencies
• Translate high-level concepts into: epics, features, and well-structured user stories with clear acceptance criteria (functional + non-functional)
• Define requirements for public and partner-facing APIs, ERP system integrations (API-only, hybrid, file-based where relevant), external tax authority APIs with differing schemas, SLAs, and behaviors
• Capture data contracts and payload expectations, error handling, retries, idempotency, versioning, authentication and authorization flows
• Work closely with engineering to ensure requirements explicitly cover: security (API keys, secrets, access control, auditability), performance and scalability, observability (logging, traceability, error visibility), compliance and regulatory constraints, backward compatibility and migration from legacy systems
• Help define requirements that allow coexistence with a legacy platform until the latter's sunset and gradual migration paths for customers and integrations
• Act as a bridge between product intent, engineering reality, external integration expectations

• Flexible working format - remote, office-based or flexible
• A competitive salary and good compensation package
• Personalized career growth
• Professional development tools (mentorship program, tech talks and trainings, centers of excellence, and more)
• Active tech communities with regular knowledge sharing
• Education reimbursement
• Memorable anniversary presents
• Corporate events and team buildings
• Other location-specific benefits

*not applicable for freelancers

• Minimum 5 years of commercial experience as a Business Analyst.
• Proven track record working on API-first products and integration-heavy B2B SaaS platforms.
• Experience managing requirements for complex ecosystems, including ERP integrations and hybrid platform coexistence.
• Deep understanding of Agile delivery, with a focus on creating "shippable" value and reducing ambiguity.
• Exceptional ability to translate technical complexity for stakeholders and collaborate effectively with architects and developers.
• Upper-Intermediate to Advanced English (written and verbal).

Nice to Have:

• Prior work in regulated domains (finance, tax, payments, compliance)
• Familiarity with ERP ecosystems (e.g. SAP, Oracle, NetSuite, Dynamics) and government or authority APIs
• Experience with event-driven or asynchronous integrations and multi-tenant SaaS platforms