Senior Full Stack Engineer
AgentJob Title: Senior Full Stack Engineer
Location: Remote (Preference for candidates based in Costa Rica)
Type: Full-time
Experience: 5+ years
Industry: B2B SaaS
About Our Client
Our client is a rapidly growing B2B SaaS company revolutionizing demand generation. Their real-time platform offers cost-per-lead media inventory at scale, along with intelligent automation to streamline campaign planning, purchasing, and management across multiple publishers.
As they expand their engineering and AI Ops teams, they are looking for experienced, hands-on engineers who thrive in fast-paced environments and love solving complex problems with scalable, modern technology.
The Role – Senior Full Stack Engineer
We’re looking for a Senior Full Stack Engineer who will be instrumental in building and scaling core features across our client’s real-time demand platform. You'll collaborate cross-functionally with product, AI Ops, and research teams to bring intelligent automation and optimization into the user experience.
You’ll work in a remote-first team, with strong ownership of your work, a startup mindset, and the opportunity to shape both product and engineering practices.
What You’ll Do
Design, develop, and maintain full-stack applications for a high-scale SaaS platform
Drive improvements in architecture, performance, code quality, and system reliability
Work closely with AI Ops and Research teams to implement smart, data-driven functionality
Champion clean code, testing, and continuous refactoring
Collaborate in an agile, feedback-driven product environment
Mentor other engineers and contribute to team growth
Tech Stack
Frontend: React, TypeScript, JavaScript
Backend: Node.js, RESTful APIs
Database: PostgreSQL, SQL
Cloud Infrastructure: AWS
Practices: Clean code, CI/CD, refactoring, testing, automation
Who You Are
5+ years of professional experience in full stack software engineering
Strong command of modern JavaScript/TypeScript, React, Node.js, and SQL/PostgreSQL
Hands-on experience with AWS or similar cloud platforms
Experience working on SaaS products, preferably in or for the U.S. market
Skilled problem-solver with an analytical mindset and a bias for action
Curious about AI and how it can enhance automation and decision-making
Comfortable in a dynamic, startup-style environment
A team player who enjoys cross-functional collaboration
Nice to Have
Experience with automation, AI Ops, or high-volume data applications
Exposure to AdTech, B2B media, or performance marketing
Contributions to developer tools or internal platforms
Creative projects or side builds that showcase initiative and curiosity
Team & Growth
Join a small, growing team: currently 4 engineers + 1 lead
High-ownership culture with room for leadership and technical growth
Collaborate with cross-disciplinary teams, including AI researchers and product leadership
Interview Process
Recruiter Interview (30 min) – Introductory conversation to learn more about you and share details about the role
Technical Assessment – A practical exercise to evaluate your coding and problem-solving skills
Team Lead Interview – Deep dive into technical experience, collaboration, and engineering practices
Product Manager Interview – Focus on cross-functional communication and product thinking
CEO Interview – Final conversation to align on vision, culture, and growth
Compensation
Salary Range: $4,500 – $6,500 USD/month
Employment Type: Full-time, Remote
Perks & Benefits
100% remote
Flexible working hours
High-impact work with ownership and autonomy
Opportunity to work on a platform powered by intelligent automation and AI
Collaborative, fast-moving team with startup energy