Founding Principle Engineer

Who are you?

already broke

only show up under real traffic

mimics prod

Numberz.ai WealthTech

Mission:

What you’ll do

What you’ll do

• Build product surfaces in

  React/Next.js + TypeScript

  and services in

  Node.js/Nest/Express

  .
• Keep contracts honest with

  TypeScript + Zod/JSON Schema

  and write

  unit/integration tests

  that run in CI.
• Design and document APIs (REST/GraphQL), add

  tracing/logging

  , and watch p95s.
• Run it in prod:

  Docker + Kubernetes

  , Postgres/Mongo, Redis; basic

  IaC

  to make it repeatable.
• Review PRs with care (old‑school eyes welcome), mentor, and keep PRs small.
• Use

  Cursor/Copilot

  to move faster—verify outputs, don’t outsource thinking.
• Work

  async‑first

  : plan your time, communicate clearly in Slack/Docs, and ship.

How we build (principles)

• Keep it small.

  Small PRs, small services (when needed), small blast radius.

• Types earn trust.

  Model the domain; make invalid states unrepresentable.

• Tests tell stories.

  Happy path + edge cases; guardrails in CI.

• Prod reveals truth—safely.

  Feature flags, canaries, synthetic load; rollbacks are a skill, not a surprise.

• Parity over excuses.

  “Works on my laptop” is banned—use containers, seeded data, contract tests, mocks to mirror prod locally.

• UAT isn’t ceremony.

  Masked prod‑like data, idempotent migrations, backfills, and chaos toggles run there first.

• GenAI is a power tool,

  not a crutch. We review, we measure.

• Infra is part of the job.

  Observability over optimism; boring deploys beat heroic fixes.

• Jargon‑light, clarity‑heavy.

  Plain words beat buzzwords.

What you bring

• 7–10 years

  building user‑facing products (preferably in startups).
• Strong

  TypeScript/MERN

  ; confident with

  Kubernetes

  in production.
• Taste for simple designs, steady delivery, and excellent code reviews.
• Solid engineering hygiene: RFC → small PR → measure → iterate.
• Ownership, time management, and crisp async communication.

Nice to have

• Fintech/wealth/trading exposure; event‑driven patterns; auth (OIDC), caching; observability (OpenTelemetry/Prom/Grafana).

Extra credit — our tiny book club

• You’ve read (and used ideas from)

  Analysis Patterns

  (Martin Fowler).
• You’ve read

  Refactoring

  (Martin Fowler) and can explain one refactor you applied.
• You bring a

  pragmatic mindset

  —tradeoffs, not dogma. (If you also like The Pragmatic Programmer, tell us a tip you actually use.)

How to apply “Founding Principal Engineer — Story Edition”

1. a time you deleted more than you wrote,
2. a test that caught a bug early,
3. a moment you kept a system simple when complexity tempted.

Include a link to a PR you’re proud of.