Senior Back-end Developer – .NET (Critical API Migration)

Niuro

Salary: Gross salary $3000 - 3500
Type: Full time

Tags: JavaScript .Net C Redis

Niuro connects projects with elite tech teams, collaborating with leading U.S. companies. Our mission is to simplify global talent acquisition through innovative solutions that maximize efficiency and quality. We empower projects by providing autonomous, high-performance tech teams, specializing in partnering with top-tier U.S. companies. We offer continuous professional growth opportunities, training in technical and soft skills, and leadership development to ensure success in innovative and challenging projects.

You will join a mission-critical backend migration effort to refactor and modernize a legacy system. The project operates under strict timelines, regulatory requirements, and a fixed database schema, demanding immediate productivity, strong ownership, and production-grade deliverables. The work is 100% remote and globally distributed, with potential for long-term collaboration upon successful completion of the initial contract.

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Key Responsibilities

Design and implement production-grade REST APIs in .NET 8+ to replace legacy Aestiva functionality.
Migrate complex business logic from Aestiva HTMLOS to modern, maintainable .NET code.
Work within a fixed database schema, optimizing queries and access patterns using Entity Framework Core.
Implement secure authentication & authorization, including session-based flows with strict timeouts (IRS 15-minute requirement).
Integrate existing payment providers (Braintree, Paymentech) into the new backend.
Shape and evolve backend solutions within predefined constraints (existing APIs, DB, compliance).
Apply Clean Architecture / CQRS pragmatically (not academically).
Write meaningful unit and integration tests for critical paths.
Collaborate closely with frontend and DevOps, defining clear API contracts.
Produce clear technical documentation (Swagger/OpenAPI, architectural notes, migration details).

What you will bring

We are seeking a highly senior, hands-on .NET backend engineer who can contribute from day one with minimal ramp-up. The ideal candidate has extensive production experience building and refactoring backend services, is comfortable operating under regulatory constraints, and can own critical components end-to-end. This role focuses on backend development, not Unity or game-oriented work. You should have a proven track record delivering scalable APIs in a highly regulated, high-stakes environment.

Required capabilities include: 5+ years of continuous, recent backend .NET experience; deep hands-on proficiency with .NET/C# in production; strong, real-world API development with a focus on performance, security, and reliability; experience with MySQL/MariaDB; advanced Entity Framework Core usage; solid knowledge of API security (JWT, OAuth2, sessions); experience with AWS (Fargate, RDS, IAM, CI/CD); ability to work autonomously with minimal guidance; comfortable working within a fixed schema and constraints; familiarity with testing strategies (unit and integration) and documentation practices (Swagger/OpenAPI).

Nice-to-have: experience with payment systems (Braintree, Paymentech), Redis/queues (SQS/RabbitMQ), regulated environments (SOC 2, PCI-DSS, GDPR), and frontend integration with Next.js/Angular.

Desirable but not required

Experience in regulated or financial systems, exposure to tax/compliance-heavy environments, familiarity with frontend integration (Next.js/Angular), and knowledge of distributed systems patterns (caching, queues, eventual consistency) are a plus. Candidates with a strong ownership mindset, excellent judgment under pressure, and a proven ability to contribute immediately in complex migrations will thrive in this role.

Benefits

We offer opportunities to work on impactful, technically rigorous industrial data projects that drive innovation and professional growth. Our remote-friendly environment prioritizes technical excellence, collaboration, and continuous innovation. Niuro supports a 100% remote work model, enabling global flexibility. We invest in career development through ongoing training and leadership opportunities, ensuring continuous growth. Upon successful completion of the initial contract, there is potential for long-term collaboration and stable, full-time employment. You will join a global community with strong administrative support, allowing you to focus on impactful work without distraction.

Informal dress code No dress code is enforced.

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Source: GetOnBoard | Main Category: Programming