Senior Fullstack .NET Developer (C#, ADO.NET , ReactJs, TypeScript)

Position Summary
We are seeking a senior full-stack developer to help modernize OT365, a mature brand operations platform used to control branding and the distribution of print and promotional items. The successful candidate will build new, maintainable platform capabilities while carefully analyzing and preserving the business-critical workflows embedded in the existing application.
This is not a greenfield project in the conventional sense. The work combines modern product development with legacy-system analysis, incremental migration, customer-specific workflow discovery, and integration with production and fulfillment systems. The developer must be comfortable working where requirements are partly documented and partly expressed through existing code, database logic, configuration, and operational practice.
About OT365
OT365 supports customer-specific product catalogs, permissions, personalization, proofing, ordering, approvals, inventory, production, fulfillment, and reporting. The platform has also been extended to support reusable event-resource scheduling, personalized data-merge products, timed multi-touch Easy Touch campaigns, analytics, and CRM-connected workflows.
Building on our MoneyGram project experience, an emerging product vision would extend OT365 to coordinated retail and multi-location brand rollouts. Potential capabilities include location-specific requirements, production and distribution of rollout materials, delivery and installation scheduling, installation-status and exception tracking, and photographic proof of completion. The detailed workflows are not yet defined and will require structured product and technical discovery.
The modernization program will establish a modern React user experience, a service-oriented .NET backend, reusable analytics, and defined integration boundaries, with Linux as the target operating system. PostgreSQL is the expected target database, but discovery must validate its feasibility, cost, performance, operational implications, and migration risk. The existing SQL Server database, Pageflex, and selected legacy components will remain important during discovery and may coexist with modernized capabilities during transition.
Primary Responsibilities
· Design, build, test, document, and support modern OT365 capabilities using .NET, C#, React, JavaScript or TypeScript, PostgreSQL, and the existing SQL Server platform.
· Develop RESTful APIs using a controller-service-model architecture with clear separation of business logic, data access, and transport concerns.
· Implement PostgreSQL data access using Npgsql and well-structured ADO.NET, with clear separation between data access and business logic rather than relying on Entity Framework or Dapper.
· Analyze the existing SQL Server schema, queries, stored procedures, data behavior, and integrations to support discovery, controlled coexistence, migration planning, reconciliation, cutover, and rollback.
· Analyze existing ASP.NET, C#, JavaScript, jQuery, SQL, stored procedure, Pageflex, and configuration-based behavior to determine the true business requirement.
· Translate legacy and customer-specific workflows into reusable platform capabilities, configuration, rules, and extension points.
· Build responsive customer-facing and administrative experiences in React.
· Support catalogs, user and group permissions, variable-data personalization, proofing, pricing, approvals, ordering, inventory, campaigns, events, production, fulfillment, and analytics.
· Participate in discovery and technical design for emerging retail and multi-location rollout capabilities without prematurely converting incomplete product ideas into fixed implementation commitments.
· Integrate with systems such as EPMS, Salesforce, HubSpot, Microsoft identity services, shipping carriers, tax services, and other customer or production platforms.
· Create automated unit, integration, and regression tests for new behavior and migration-critical workflows.
· Use Cursor AI as an integral development tool, creating and following project plans, rules, skills, and other repository guidance while independently validating generated code and technical decisions.
· Develop, deploy, diagnose, and support the application in a Linux-based runtime environment.
· Participate in Jira-based Agile delivery, including backlog refinement, estimation, sprint planning, daily coordination, code reviews, defect investigation, deployment, and production stabilization.
· Document technical decisions, service contracts, data flows, operational procedures, and discovered legacy behavior.
· Communicate risks and uncertainties early, propose options, and take ownership of work through verification and production readiness.
Required Technical Qualifications
· Strong professional experience developing production applications with C# and modern .NET.
· Strong React experience, including component design, state management, API integration, forms, validation, and responsive user interfaces.
· Strong PostgreSQL skills, including relational design, complex queries, transactions, indexing, performance analysis, concurrency, and operational troubleshooting.
· Strong SQL Server skills sufficient to analyze and migrate a mature production schema, stored procedures, queries, data behavior, and integrations.
· Practical experience with Npgsql and ADO.NET, or the ability to work effectively within an ADO.NET-based data-access standard.
· Experience migrating production data and application behavior between database platforms, preferably from SQL Server to PostgreSQL.
· Experience designing and consuming REST APIs and integrating with third-party systems.
· Experience modernizing, decomposing, or incrementally replacing a mature legacy application.
· Working knowledge of authentication, authorization, role-based access, secure coding, logging, auditing, and error handling.
· Experience with Git-based development, pull requests, code review, CI/CD pipelines, and disciplined release practices.
· Demonstrated experience using Cursor AI for production software development, including creating and adhering to Cursor plans, rules, skills, and project-specific instructions.
· Experience working with Jira and delivering software through an Agile development process.
· Ability to diagnose behavior across the browser, API, application services, database, scheduled processes, and external integrations.
Professional Qualifications
· Demonstrated ownership: follows work from requirement through implementation, verification, documentation, and production support.
· Strong analytical and reverse-engineering ability; does not require perfectly documented requirements before making progress.
· Clear written and verbal English communication with both technical and nontechnical stakeholders.
· Able to work effectively with a distributed U.S. and India team and maintain reliable scheduled overlap.
· Comfortable asking precise questions, documenting assumptions, and distinguishing confirmed behavior from inference.
· Customer-oriented judgment and respect for the operational consequences of changes to a production platform.
Preferred Experience
· ASP.NET Framework 4.8, JavaScript, jQuery, or migration from older Microsoft web stacks.
· Familiarity with Linux command-line tools, application configuration, process and service management, logs, networking, permissions, scripting, deployment, and troubleshooting.
· Pageflex, variable-data publishing, document composition, PDF or bitmap proof generation, or another rendering engine.
· Print, promotional products, marketing operations, web-to-print, inventory, production, or fulfillment workflows.
· CRM integrations, particularly Salesforce or HubSpot.
· Dashboards, reporting, analytics, exports, or integration with business-intelligence tools.
· Multi-tenant or highly configurable B2B SaaS applications with customer-specific rules and permissions.
· Retail rollout, field service, installation coordination, location management, photographic verification, proof-of-completion, or exception and rework workflows.
· SQL Server-to-PostgreSQL migration, including data-type mapping, sequence and identity behavior, stored-procedure replacement, validation, reconciliation, coexistence, cutover, and rollback.
· Azure or comparable cloud infras

Work arrangement
No