Senior Backend Developer (.NET)

About the Role

The company is a B2C gaming startup building a high-performance sweepstakes platform already serving real users. The system handles real-time transactions at scale in a regulated space — reliability, speed, and security are paramount. The company operates lean, with backend engineers owning their services from architecture to production. Engineers here don't just implement — they design, decide, and ship. The company is looking for a Senior Backend Developer with 5+ years of experience who wants real ownership over systems that matter. This isn't a ticket-taking role — you'll be driving system design, making tech stack decisions, and shaping the architecture of a live, real-money gaming platform. You'll design and build backend services using .NET 10, own features end-to-end from architecture through production, and work directly with product, business, and compliance stakeholders. You'll be expected to identify the right tool for the job — whether that's choosing between Postgres and MongoDB for a given flow, deciding when WebSockets beat HTTP, or deciding what doesn't need to be built at all.

Responsibilities

• Lead system design and architecture for backend services using .NET 10
• Choose the right tech stack for each problem and justify those decisions
• Architect scalable, secure, and high-performance APIs and real-time systems
• Design data models and flows across PostgreSQL and MongoDB based on access patterns, consistency needs, and scale
• Build real-time gameplay and transaction features using WebSockets and event-driven patterns
• Apply backend best practices — clean architecture, SOLID, KISS, testing, logging, and monitoring — pragmatically, not dogmatically
• Own features end-to-end — from architecture and implementation through deployment, monitoring, and iteration in production
• Manage CI/CD pipelines and AWS infrastructure for the services you own
• Collaborate directly with product, business, and compliance stakeholders to shape what gets built
• Use AI coding agents (Claude Code, Codex, Cursor, etc.) to raise both velocity and quality

Requirements

• 5+ years of backend development experience, with strong fluency in modern .NET (C# / .NET 6+)
• Demonstrated experience owning system design and architecture decisions on production systems
• Strong experience with both PostgreSQL and MongoDB — including schema design, indexing, and choosing between them based on workload
• Experience building real-time systems with WebSockets
• Track record of taking complex features end-to-end: design, implementation, deployment, and production ownership
• Ability to choose and justify a tech stack rather than just consume one
• Strong analytical and problem-solving skills, with a bias toward simple, correct solutions
• Comfortable with full ownership in a lean startup environment — no hand-holding, no hiding
• Experience with or strong willingness to adopt AI coding tools
• Independent, proactive, opinionated, and solution-oriented

Nice to Have: 

• Experience in gaming, sweepstakes, fintech, or high-scale B2C platforms
• Experience with AWS (ECS, RDS, etc.)
• Experience with message queues and event-driven / asynchronous architectures
• Experience designing for regulated environments (compliance, auditability, PII handling)

About the Company

The company is a B2C gaming startup building a high-performance sweepstakes platform already serving real users. The system handles real-time transactions at scale in a regulated space. They operate lean, with a small, senior team and minimal bureaucracy, allowing decisions to be made quickly. The environment is fast-paced and focuses on meaningful ownership over core systems.