Senior Full-Stack (Ruby on Rails) Engineer

Senior Full Stack Engineer (Retail Platform Modernization)

• Location: Remote
• Role Type: Full-Time / Product Development
• Industry Domain: B2B Wholesale Grocery Marketplace & Tech-Enabled Supply Chain
• Project Timezone: US Eastern Time

Role Overview
We are seeking a highly skilled, adaptable Senior Full Stack Engineer to play a lead execution role in modernizing and scaling our client's digital wholesale marketplace.
In this role, you will be deeply involved in both Immediate Risk Containment and Ongoing Modular Architecture Evolution & AI-Driven Scaling. You will work across the full stack, securing existing backend APIs, establishing automated delivery pipelines with DevOps, decoupling legacy services and APIs into high-performance microservices.

Project Roadmap

Current Platform Stabilization:

• Eliminate security exposures by enforcing strict server-side Role-Based Access Control (RBAC) and rotating production secrets.
• Implement cryptographic signature verification and defensive API checks across all third-party inbound webhooks.
• Secure core financial and transactional workflows.

Modular Evolution & Scaling:

• Decouple legacy monolithic core services into modular, high-throughput microservices using modern systems architecture.
• Alongside with DevOps, establish automated CI/CD build and release pipelines and automated end-to-end smoke testing suites.
• Integrate AI-driven automation workflows into daily platform operations, and LLM-assisted developer workflows.
• Consult DevOps on AWS optimization for high availability, API performance, and zero-downtime deployments.

Technical & Domain Requirements

Must-Have Experience & Skills:

• Retail & B2B Wholesale Domain Knowledge: Strong understanding of multi-tenant B2B marketplaces, inventory ledgers, order lifecycle states.
• PostgreSQL Expertise: Deep proficiency in relational database architecture, ACID transaction management, indexing strategies, advisory/row locking, and schema migrations.
• AWS Cloud Ecosystem: Hands-on experience deploying cloud-native applications to AWS (RDS PostgreSQL, EC2, S3, ElastiCache Redis, Lambda, IAM, and containerized deployments).
• AI-First Development Principles: Daily use of modern AI engineering tools (e.g., Cursor, Codex, Claude Code) to accelerate code generation, refactoring, automated test suite creation, and system documentation.
• RESTful APIs & Third-Party Integrations: Extensive experience building and consuming resilient webhooks and RESTful APIs, with specific experience handling Stripe, Shopify, SendGrid, HubSpot, etc.
• Modern Stack Adaptability (Rust): Strong willingness and enthusiasm to learn and write production microservices in modern high-performance systems languages, specifically Rust, as part of our long-term microservice modernization strategy.

Good-to-Have Experience (Legacy System Context):

• Ruby on Rails: Experience reading, debugging, and extracting business logic from legacy Rails monolithic backends.
• Nuxt 2 / Vue.js / Node.js: Familiarity with Nuxt 2 (SSR/SPA), Vue 2/3, and Node.js environments to facilitate backend service decoupling.

Team Structure & Collaboration Model
You will join a new engineering pod in Ukraine designed for high-velocity delivery without bureaucratic overhead.

Teammates You Will Work Alongside:

• Solution Architect / Technical Advisor: Provides high-level platform strategy, guidance, and advisory on AI-first development.
• Senior DevOps Engineer: Partners with you on CI/CD pipeline construction, multi-VPC environment isolation, containerized release builds, and IaC reconciliation.
• Senior Full Stack (front end): Focuses on web marketplace UI/UX, vendor portal features, and design system components.
• QA Automation Engineer: Builds CI/CD quality gates, automated smoke suites, and regression testing pipelines.

Communication & Business Stakeholder Interaction:

• Translating Tech to Business: You will also work with non-technical executive leadership (CEOs, Founders, Operations, and Sales/Marketing leads) to brainstorm the best ways for business ideas realisation.
• Agile Autonomy: Participate in lightweight sprint planning, direct code reviews, and continuous delivery loops, taking direct ownership of end-to-end features from technical design to production deployment.

We Offer

• Opportunity to propose solutions and influence technical decisions
• Dynamic and challenging tasks
• Team of experienced professionals
• Competitive salary
• Low bureaucracy
• Continuous self-improvement
• Long-term employment with paid vacation and social benefits
• A bunch of perks 😊