Digital Transformation Functional Analyst - API & Modularity

Keystone Solutions; Brussel; Hybrid; EUR 60,000 - 90,000; Full time

Job summary

Keystone Solutions is seeking a Functional Analyst consultant for a strategic transformation project with a major client. You will bridge business needs and IT, designing and evolving systems for billing, revenue, and revenue assurance, while enabling front-end teams through robust APIs and modular services.

Based in Brussels, the role features a hybrid model (3 days in office, 2 days remote). You will translate complex requirements into modular specifications, work with architects and

Qualifications

• Proven experience as a Functional Analyst, Solution Analyst, or similar role in complex IT environments.
• Strong modeling skills: UML, BPMN, API specifications (e.g., Swagger/OpenAPI).
• Experience working with modular, service-based, or domain-driven architectures.
• Ability to structure, summarize, and challenge information and requirements.
• A critical thinker with a strong sense of ownership and curiosity.
• Excellent communication skills in English (written and spoken).

Responsibilities

• Analyze and model business processes using UML, BPMN, and API modeling tools.
• Translate business needs into functional specifications that are modular, service-oriented, and technically coherent.
• Collaborate with architects, developers, and business stakeholders to ensure end-to-end process alignment.
• Challenge and refine requirements to ensure they are complete, consistent, and aligned with architectural principles.
• Ensure functional continuity across systems and teams — not just within your own scope.
• Support the transformation from legacy systems to modular, API-driven architecture.
• Document and communicate complex information in a structured and accessible way.
• Contribute to testing strategies and validate functional deliverables.

Skills

Functional Analyst

UML

BPMN

API specs

Modular architecture

Requirements structuring

English communication

Tools

Sparx EA

Draw.io

Postman

API gateways

Job description

Keystone Solutions is seeking a Functional Analyst consultant for a strategic transformation project with a major client. You will bridge business needs and IT, designing and evolving systems for billing, revenue, and revenue assurance, while enabling front-end teams through robust APIs and modular services.

Based in Brussels, the role features a hybrid model (3 days in office, 2 days remote). You will translate complex requirements into modular specifications, work with architects and