Senior Full Stack Engineer

The company

Coastline Digital is a software engineering and AI consulting company based in San Diego, CA, working with an international team of experienced engineering professionals. We help companies design, build, and scale custom software, AI and machine learning systems, cloud and data platforms, and enterprise applications built to perform reliably in daily production use. Our engineers work directly with client stakeholders to understand real workflows, and we deliver in short, iterative cycles so clients see working results early.

The role

The Senior Full Stack Engineer contract role is a fully remote position focused on building and operating our agent platform, the AI infrastructure agents depend on, and the developer tooling our builders use every day.

What you’ll do

• Develop and operate our Agent Platform for deploying, running, evaluating, governing, and improving agents and agentic workflows.
• Establish and operate the AI Infrastructure that agents depend on: LLM and MCP gateways with guardrails, fallback, usage and cost controls, and model rollout policies.
• Build and operate agents and workflows that carry engineering work from issue to production and business work from trigger to outcome, with humans governing the boundaries.
• Own our Developer Infrastructure (Source Control and CI) and build the developer tools that improve builder flow and reduce friction across the company.
• Partner with teams across Engineering, Product, Sales, and G&A to understand where AI could accelerate their work or improve the quality of outcomes.
• Drive adoption of agents and agentic tooling across the company, and own the best practices and enablement materials that help builders succeed using the paved roads.
• Build measurement and feedback loops (usage, reliability, and cost) to quantify the productivity the platform unlocks and guide the roadmap.
• Participate in on-call to support internal users.

What you’ll bring

• Strong, production-level proficiency in both Python and .NET (C#), the most important skills for this role. Experience with Go, TypeScript/JavaScript, or Java is a plus.
• Strong software engineering fundamentals and experience shipping and operating production-quality internal platforms or developer tooling.
• Experience leveraging modern agentic coding tools such as Codex and Claude Code.
• Experience building workflow automation or internal tools (CLI tools, services, GitHub automation, cloud automation, or similar).
• Strong judgment about when to standardize versus when to enable flexibility, and how to remove friction without compromising reliability.
• Comfort working cross-functionally, including partnering with non-traditional developers and translating needs into usable solutions.
• Ability to use data and qualitative feedback together to prioritize and measure impact.
• Clear written communication, including documentation that enables self-service.

Nice to have

• Experience building internal agents and operating an agent platform.
• Experience building and operating Temporal applications.