Freelance Senior .NET Developer / Tech Lead

Wise Integration; United States; On-site; USD 46,000 - 77,000; Full time

Job summary

Lever, Inc. is seeking a Senior .NET Developer / Tech Lead to join our engineering team in a payment-focused fintech environment. You will design and build backend services using C# / .NET, mentor peers, and influence architectural decisions.

The role covers REST API integrations, SQL databases, Docker, and CI/CD, with a focus on secure, scalable systems. Start ASAP for a 12-month engagement, in a regulated fintech context.

Qualifications

• 7+ years of hands-on C# / .NET experience.
• Strong backend development experience with REST APIs and distributed systems.
• Proficiency with SQL databases and relational DBs.
• Experience with Docker and CI/CD pipelines.
• Ability to own technical direction and guide other developers.

Responsibilities

• Design and develop backend services using C# / modern .NET.
• Contribute to technical design and architectural decisions.
• Build integrations with REST APIs, third-party platforms, messaging, and file interfaces.
• Ensure code quality through code reviews and best practices.
• Mentor developers and lead technical discussions.
• Collaborate with product, compliance, QA, and other engineering teams.

Skills

C# / .NET

Backend development

REST APIs

SQL

CI/CD

Docker

Technical leadership

Mentoring

Tools

Azure

AWS

CI/CD tooling

Git

Job description

Project/Client:Fintech

Location:Lithuania

**Start Date:**ASAP

Duration:12 months

**Language:**English

Role Overview:

We’re looking for a Senior .NET Developer / Tech Lead to join our engineering team and build payment-focused backend solutions in a regulated fintech environment. This is a hands-on role combining software development with technical leadership. You’ll design and develop backend services, contribute to technical and architectural decisions, and help the team maintain high engineering standards.

Key Responsibilities:

• Design and develop backend services using C# / modern .NET
• Contribute to technical design and architectural decisions
• Build integrations with REST APIs, third-party platforms, messaging, and file-based interfaces
• Ensure code quality through code reviews and engineering best practices
• Mentor developers and lead technical discussions
• Work with SQL, relational databases, CI/CD, and Docker
• Build secure, reliable, and scalable software solutions
• Collaborate with product, compliance, QA, and other engineering teams

Must-Have Requirements:

• 7+ years of hands‑on C# / .NET experience
• Strong backend development experience
• Experience with REST APIs, integrations, and distributed systems
• Strong SQL and relational database experience
• Experience with Docker and CI/CD
• Understanding of secure and reliable software development
• Experience as a Senior Engineer, Tech Lead, or similar
• Ability to take technical ownership and guide other developers

Nice to Have:

• Experience in payments, banking, fintech, or financial services
• Experience in a regulated / compliance-driven environment
• Knowledge of ISO 20022 / SEPA
• Understanding of clearing, settlement, or payment processing
• Experience with Azure or AWS

€30 - €50 an hour