We build AI research agents that can discover, link, and reason over everything about people and companies. The platform turns that intelligence into automated research workflows for sales, recruiting, and marketing.

About us

Sixtyfour AI is a small, fast-moving team building real products for real users. We ship quickly, sweat the details, and give engineers full ownership—from idea to production.

The role

We’re hiring a full-stack engineer who loves taking products from 0→1 and then making them great. You’ll own features end-to-end, work closely with design and founders, and make pragmatic technical decisions that balance speed and quality. If you’ve built things outside of school/work, launched side projects, or tried something entrepreneurial, we want to talk.

What you’ll do

• Build polished, fast product experiences in Next.js + TypeScript (accessible, responsive, design-quality UI).
• Design clear backend contracts and APIs in FastAPI/Python for workflows, jobs, billing, and auth.
• Evolve our workflow engine (DAG/state machine): scheduling, retries/idempotency, rate limits, progress, logs, user-visible run history.
• Ship data pipelines and background workers (Celery/queues) with strong observability and alerting.
• Scale and harden on AWS + Docker (ECS/EKS or similar), adding Redis caching, pagination, backpressure, and cost controls.
• Implement features end-to-end: DB schema → API → UI, including tests and telemetry.
• Contribute to billing (Stripe), permissions/RBAC, and real-time UX (SSE/WebSockets) for run status.
• Hold a high bar for reliability, performance, and UX—instrument everything, measure, and iterate.

You’ll thrive here if you have

• Proven ownership: you’ve shipped projects end-to-end (products, startups, open-source, freelancing, apps with users).
• Strong backend Python (FastAPI preferred): API design, testing, error handling, schema/versioning.
• Cloud + containers: deployed/operated with Docker and a major cloud (AWS preferred: ECS/EKS/Lambda, SQS, CloudWatch).
• Workflow/job systems experience: queues, retries, idempotency keys, scheduling, and run histories.
• Data stores: comfortable with Postgres schema design and Redis (caching, rate limiting, locks).
• Performance mindset: RSC/Server Actions, data-fetching patterns, bundle/TTFB tuning, DB query perf.
• Production observability: logs, traces, metrics (e.g., OpenTelemetry, Sentry, Langfuse) and pragmatic on-call.
• Security hygiene: PII handling, secrets, JWT/session auth, CSRF/CORS, least-privilege access.

Nice to have

• Next.js App Router, RSC, Server Actions, edge/runtime primitives (Vercel/CloudFront).
• Prisma/Drizzle; tRPC or GraphQL; Zod/JSON Schema; feature flags/experimentation.
• Real-time UX (WebSockets/SSE), optimistic updates, background revalidation.
• Celery/RQ, event sourcing, or state-machine libs (Temporal, Dagster, Prefect, XState).
• Stripe (subscriptions, metered usage, webhooks) and customer-visible billing pages.
• CI/CD (GitHub Actions), IaC (Terraform), lightweight cost/perf dashboards.
• Search/retrieval (OpenSearch/Elasticsearch) and simple relevance tuning.
• Testing: Playwright (e2e), Vitest/Jest, pytest; accessibility checks.

How we work

• Ownership > bureaucracy: small team, big impact.
• Speed with quality: ship, measure, iterate.
• Customer-obsessed: polish the details that matter.

Interview process

1. Quick screening call (mutual fit + role context).
2. Take-home assessment (focused, practical).
3. Code walkthrough (discuss decisions, trade-offs, and improvements).
4. In-person paid trial week (work with us on real problems; compensated).

What to include when you apply

• A few links that show initiative and ownership: GitHub, product pages, demos, write-ups, or anything you’ve shipped.
• A short note on a 0→1 project you led: goal → constraints → your decisions → outcome.

Language Models, Opensearch/Elasticsearch, Next.js (typescript), Python, FastAPI, AWS, Docker, Celery workers, Playwright, Supabase, Stripe