Senior Full-Stack Engineer

Overview Plus8soft is a global engineering company providing outstaffing and outsourcing services for fast-growing startups and established international companies. We focus on delivering high-quality engineering talent across Web, Mobile, Cloud, AI/ML, and DevOps with a strong presence in the US and global markets. We're looking for a Senior Full-Stack Engineer to join a team modernizing and scaling a production marketplace platform. This role is for an engineer with a legacy-first mindset — someone who can navigate existing codebases with confidence, extract business logic, and incrementally migrate toward modern architecture without breaking what already works. You'll work across the full stack, owning both backend services and frontend SPAs in a collaborative, distributed engineering environment. Key Responsibilities Design, develop, and maintain scalable backend services using Node.js, TypeScript, NestJS, and ExpressBuild and maintain frontend SPAs using React, TypeScript, and ViteOwn and optimize MySQL database schemas, queries, and AWS RDS configurations including Multi-AZ and read replicasIntegrate and maintain third-party payment systems and financial workflowsManage and work within AWS infrastructure including EC2, RDS, S3, Secrets Manager, and IAMNavigate and extract business logic from legacy codebases as part of incremental modernization effortsCollaborate with product and engineering stakeholders to translate requirements into reliable, maintainable solutionsParticipate in code reviews, technical planning, and architecture discussionsContribute to technical documentation and knowledge transfer across the teamRequirements 5+ years of overall engineering experience with 2+ years focused on backend engineeringProduction-grade experience with Node.js and TypeScript, NestJS and Express, MySQLProduction experience with React and TypeScript for frontend SPA developmentExperience with payment integrations (payment gateways, payout flows, or similar)Hands-on experience with AWSLegacy-first mindset to be comfortably working within and around existing systemsExperience building and maintaining Vite-based SPAsHands-on experience with AI-assisted engineering toolsFluent English skillsNice-to-have requirements Ability to read and extract business logic from PHP / CodeIgniter codebasesDomain experience in marketplace or two-sided platforms: orders, carts, commissions, payouts, and settlementsExposure to Middle East or KSA client environments and Arabic localisation awarenessConditions 100% remote role with a flexible schedule (APAC and European time zones welcome)Full-time contractor engagementCompensation in USD via a convenient payment methodDirect collaboration with founders and fast decision-makingHigh level of ownership within a production platform undergoing active modernization