Senior Full-Stack-ReactTypeScript

Working Hours: U.S. Business Hours Interview Process: 3 Rounds Role OverviewWe are seeking a hands-on Senior Full-Stack / Platform Engineer to perform a deep technical assessment of an existing multi-tenant SaaS marketplace platform.The engineer will work directly with the Solution Architect and AI Engineer to review the application codebase, database, APIs, security controls, CI/CD, test posture, performance and operational readiness. The immediate objective is assessment and recommendations, not feature development or remediation.Key ResponsibilitiesApplication & Codebase AssessmentPerform detailed review of the existing frontend and backend codebase.Assess code quality, maintainability, consistency and technical debt.Review application architecture against established domain and data-access patterns.Identify code paths that bypass expected platform conventions or security boundaries.Validate findings through code tracing and non-production reproduction where appropriate.Multi-Tenancy & Data IntegrityReview organization/tenant-scoped data-access patterns and PostgreSQL Row-Level Security (RLS).Identify potential cross-tenant data-exposure paths.Review database schemas, migrations, foreign keys, soft deletes and data-integrity patterns.Assess schema-first migration discipline and potential schema drift.APIs, Integrations & ScaleReview Partner APIs, Edge Functions, webhooks and external integration patterns.Assess API authentication, authorization, error handling and scalability.Review whether the current architecture can support an API-centric integration model.Identify N+1 queries, over-fetching, indexing gaps, realtime fan-out and Edge Function latency risks.Assess frontend bundle size, code splitting and likely platform scaling constraints.Test, CI/CD & Operational ReadinessAssess unit, integration and security test coverage, including RLS negative-test scenarios.Review CI quality gates including type checking, linting, tests and dependency/security scanning.Identify weak or misleading AI-generated tests.Review logging, monitoring, observability, backup/recovery, environment consistency and rollback capability.Assessment DeliverablesDocument evidence-backed findings with severity, affected components and recommended remediation.Reproduce technical findings where feasible in non-production environments.Contribute to the hardening scorecard, findings register and prioritized 30/60/90 roadmap.Support the Solution Architect in estimating remediation complexity for the subsequent execution phase.Required Technical Skills & Competencies7+ years of hands-on full-stack software engineering experience.Strong proficiency in React and TypeScript.Strong experience with PostgreSQL, SQL and relational data modelling.Experience with modern serverless/backend platforms and API development.Strong understanding of authentication, authorization and multi-tenant SaaS architecture.Practical experience with database Row-Level Security or equivalent data-access controls.Strong REST API and integration experience.Experience with CI/CD pipelines and GitHub-based development workflows.Strong debugging, code-review and root-cause-analysis capability.Experience assessing production applications for scalability, security and maintainability.Good to HaveHands-on Supabase experience including Postgres, Auth, Storage, Realtime and Edge Functions.Experience with Vite, TanStack React Query, Tailwind or similar modern frontend frameworks.Experience with Cloudflare Pages.Exposure to Mapbox, messaging platforms and third-party API integrations.Experience with marketplace, logistics, disaster-response or workflow platforms.Experience supporting AI-enabled applications and familiarity with MCP / agent integrations.Exposure to public-sector or regulated application environments.Must-Have SkillsReact + TypeScript.PostgreSQL and strong SQL/data modelling.API and integration engineering.Authentication, authorization and multi-tenancy.Strong code-review and troubleshooting capability.CI/CD and engineering quality practices.Ability to assess rather than immediately rewrite existing systems.Ability to work during U.S. business hours.Desired AttributesStrong hands-on engineering mindset.Curious and evidence-driven when investigating unfamiliar code.Able to separate genuine platform risk from stylistic technical preferences.Strong ownership and attention to detail.Comfortable working with architects and AI engineers on cross-cutting findings.Clear communicator capable of explaining technical issues and remediation options.