Denis Sefer

Developed and user-tested full-stack features with HTML, CSS, JavaScript, React, and Node.js; collaborated with support to reproduce and fix customer issues; documented solutions in concise how-to guides; and tracked all work in Git and Jira within an agile, ITIL-aligned workflow.

Delivered front-line sales and customer support for mobile, internet, and TV services; consistently surpassed monthly targets, resolved tickets end-to-end in the CRM, and coached new hires on products and care procedures.

Provided Tier-1 technical assistance for broadband and mobile users, achieving high first-call resolution and CSAT scores while escalating complex faults with clear diagnostics for quicker Tier-2 closure.