Sr. Full Stack Engineer - Backend, Data & Infrastructure

Sr. Full Stack Engineer - Backend, Data & Infrastructure

Location: Kansas City (onsite in Overland Park, KS)

Salary: $115K - $160K base plus equity

Summary:

Our client is a customer-obsessed startup hiring a Sr. Full Stack Engineer focused on the services behind it all: real-time messaging, data and AI, and the cloud infrastructure that keeps things running.

This is a fast-moving team that leans heavily on AI and automation to build devices, applications, and platform. You'll spend most of your time specifying, orchestrating, and reviewing AI coding agents rather than hand-writing code. Your value is judgment: breaking problems into work agents can execute, writing precise specs, reviewing and evaluating output, and owning the architecture and safety calls agents can't make. That judgment comes from shipping hard systems for real users, which is why this role is senior-only.

Responsibilities:

• Customer problem first . Work starts from a real, validated customer need — a working demo or a clear spec grounded in what the frontline actually does. You keep that problem in view the whole way, not just the ticket.
• Spec-driven, not prompt-driven . You turn the validated requirement into structured specifications that drive what the agents produce. Ad-hoc prompting doesn't scale and isn't how we work.
• You orchestrate; agents execute . You decompose the work, sequence it, and keep the big picture; bounded agent execution does the building. You own the meta-level decisions — sequencing, architecture, tradeoffs.
• Review and evaluation are the job . You review generated code critically, catch the compatibility, safety, and performance failure modes that matter here, and build the tests and evals that gate quality. On four-nines paths and services that older clients in the field still depend on, that scrutiny is the work.
• Weekly releases behind flags . Merge to main continuously; releases go out weekly behind feature flags — live but dark until product turns them on for a customer site.

Technical strengths in one or more of the below:

• Real-time services — Node, MongoDB, Redis, MQTT messaging; low-latency, high-availability services.
• Data & AI — streaming data pipelines, warehouse management, server-side AI models.
• Cloud infrastructure — Azure, Kubernetes, Terraform; deployment, observability and reliability for always-on services.
• Distributed systems — caching, message queues, load balancing.
• Location & safety services — processing GPS, bluetooth beacon and ultra-wideband data into precise tracking and safety alerting.

Requirements:

• Several years of senior-level engineering with a track record of shipping production systems.
• Demonstrable agentic development experience.
• Strong systems judgment: APIs and data models, backward/forward compatibility, performance under real-world constraints.
• Comfort in a monorepo with continuous delivery, feature flags, canary releases, and automated testing as the release gate.
• Strong testing and automation experience, specifically validating service performance and reliability at scale, API and integration tests, and CI/CD test integration.
• Customer obsession. You want to see the work in the user's hands. You measure yourself by whether the customer's problem is actually solved — not by whether the feature shipped.
• Agentic judgment. You know what to delegate and what to own. You write specs that produce correct results, you review generated code as rigorously as your own, and you never ship what you can't vouch for.
• High agency. You take ownership and do whatever it takes to drive a problem to resolution, without waiting for direction.