Full Stack Engineer

CrowdPass Senior Software Engineer, Platform Lead

CrowdPass | New York, NY | Full-time | Hybrid

About CrowdPass

CrowdPass is an event operations platform for access control, ticketing, and attendee management. Founded in 2021 in New York, we power the door at live events: NFC wristbands, handheld readers, QR check-in, badge printing, and the organizer dashboard behind all of it. When check-in breaks, it breaks in front of thousands of people. Reliability at the gate is the product.

The role

You will be the technical owner of the entire CrowdPass platform: the web dashboard, the .NET API, the mobile app door staff use at the gate, the edge services that talk to readers and printers, and the AWS infrastructure underneath. You will make the architecture decisions, review every change, run production, and write much of the code yourself.

This is a hands-on role on a small team. The platform works in the field today and has a documented debt backlog. It needs one senior engineer who can hold all of it in their head and make it better every week.

The platform

• Web dashboard and public pages. Next.js 15, React 19, TypeScript, Tailwind, Radix, TanStack Query. Event setup, attendees and tickets, Stripe checkout, gate rules, badge and email designers, a microsite builder, SMS and email campaigns, analytics, billing, a super-admin console, and an AI assistant. Deploys on AWS Amplify.

• Backend API. .NET 9 Minimal APIs, EF Core 9 on PostgreSQL, MediatR (CQRS), Hangfire, Cognito passwordless auth plus machine-to-machine tokens for devices. Row-level multi-tenancy on a shared database. Integrates Stripe, Twilio, SendGrid and SES, S3, OpenAI, and ticketing partners.

• Mobile app (iOS and Android). Expo SDK 57, React Native, TypeScript strict, Redux and saga, React Query, Zustand. Phone NFC, BLE handheld readers, QR and OCR scanning, Zebra badge printing, and a DSLR photobooth mode. Offline-first check-in with a local snapshot and a replayed write queue. Ships via EAS with over-the-air updates for event-day fixes.

• Hardware and edge. ESP32 reader firmware (ESP-IDF, C) with OTA updates, a Node WebSocket middleware that bridges readers to the API, an Electron print agent for venue laptops, and AWS Lambda services for badge PDFs, wallet passes, and partner attendee sync (DICE, Splash).

• Infrastructure. AWS (ECS, RDS, S3, Cognito, SES, Lambda, CloudWatch, Amplify), GitHub Actions, Sentry, PostHog. A Terraform repo exists but has drifted from what runs; reconciling it is an early project.

What you will do

• Own production. Know why the gate is slow at 7pm on a Saturday and fix it. Build the alerting and runbooks that make that rare. Be reachable during major customer events.

• Own the architecture. Decide how features get built across web, API, and mobile. Keep the tenant boundary, the auth pipeline, and the offline check-in path correct as the product grows.

• Close the backlog. Each repo has a ranked gaps document. Triage it and work it down, starting with secrets management, authorization defaults, and production redundancy.

• Harden releases. Grow test coverage where it matters (tenant isolation, checkout, check-in, offline sync), get the gates green, and make deploys boring.

• Ship features. Ticketing, partner integrations, the AI event builder, designers, analytics, and whatever the next large customer needs. Test in a real browser and on a real device before calling it done.

• Set the bar. Code review, conventions, documentation, and onboarding for the engineers who join after you.

What we are looking for

• 7+ years building and running production software, with at least 3 years owning a system end to end.

• Deep experience in .NET (ASP.NET Core, EF Core, PostgreSQL) and in TypeScript and React. You will be in both every week.

• Production React Native or Expo experience, including native modules, BLE or NFC, and app store and OTA release flows. This is required.

• Strong grasp of multi-tenant SaaS correctness: data isolation, authorization, audit trails.

• Hands-on AWS operations and the ability to debug a production outage from logs and metrics.

• Stripe experience (Checkout, Connect, subscriptions, webhooks).

• Comfort with offline-first and eventually consistent designs: queued writes, idempotency, replay.

• A track record of taking over an existing codebase and improving it without a rewrite.

• Clear written communication. Our architecture docs are how the team thinks; you will maintain them.

Nice to have

• Hardware-adjacent software: BLE, NFC, device fleets over WebSockets, firmware OTA, printers.

• Live events, ticketing, or venue operations, or another domain where software fails in public.

• Background job systems at scale, PDF and label generation, Terraform, embedded C on ESP32.

• Experience using AI coding agents well, with strong conventions, review, and gates.

How we work

Small team, high trust, direct communication. We test on real hardware and in real browsers before we call something done. Event days are sacred: we do not deploy during a customer's doors-open window without a reason.

Salary: $80,000 - $110,000+ in addition to stock & equity participation.