Senior Software Engineer (Fullstack) (SaaS)

TL;DR

Senior Software Engineer (Fullstack) (SaaS): Architecting, building, and shipping end-to-end product features, owning everything from frontend UI to backend logic and API design. Focus on driving technical excellence for the frontend experience, including performance, accessibility, responsiveness, and overall quality.

Location: Hybrid work in Lisbon, Portugal

Company

Datadog is a global SaaS business delivering a rare combination of growth and profitability.

What you will do

• Architect, build, and ship end-to-end product features—owning everything from frontend UI to backend logic, data modeling, and API design.
• Drive technical excellence for the frontend experience, including performance, accessibility, responsiveness, and overall quality.
• Collaborate with product managers, designers, and backend engineers to define user experiences, data flows, and APIs.
• Improve the reliability and scalability of services that support your features, contributing backend code where needed.
• Lead technical discussions, influence architecture decisions, and mentor other engineers on fullstack patterns and best practices.
• Ensure strong testing coverage, clear documentation, and long-term maintainability across the stack.

Requirements

• You have 6+ years of experience building and shipping production-grade fullstack features at scale.
• Deep expertise in JavaScript/TypeScript and modern frontend frameworks (React preferred).
• Solid backend engineering skills with proficiency in at least one server-side language (e.g., Python, Go, Java) and familiarity with APIs, databases, and distributed systems.
• Ability to interpret broad product requirements and translate them into polished, user-facing applications.
• Strong understanding of frontend architecture, state management, performance tuning, and client-server interaction patterns.
• Excellent communicator with the ability to lead design and architecture discussions in a collaborative, cross-functional environment.

Culture & Benefits

• Generous and competitive benefits package.
• New hire stock equity (RSUs) and employee stock purchase plan.
• Continuous career development and pathing opportunities.
• Employee-focused best in class onboarding.
• Internal mentor and cross-departmental buddy program.
• Friendly and inclusive workplace culture.