Senior Software Engineer (Warsaw)

TechTree; Warszawa; Hybrid; PLN 240,000 - 300,000; Full time

Job summary

TechTree is building an AI-native platform to modernize aerospace, electronics, industrial and defense supply chains. We seek a seasoned Full-Stack Engineer to design, build, and maintain features end to end, from schema to UI, collaborating with the platform and field teams to integrate with legacy ERP and email-driven workflows.

You will ship real products, work with TypeScript and frontend frameworks, and autonomously handle complex SQL tasks.

Qualifications

• 5+ years of genuine full-stack experience.
• Have shipped real full-stack products (GitHub repo, live app, or Loom walkthrough).
• Strong in TypeScript and at least one frontend framework (React, Svelte, Next, etc.).
• Comfortable in SQL, preferably Postgres; can write, optimize, and debug complex queries.

Responsibilities

• Design, build and maintain features end to end, from schema to UI.
• Run several projects in parallel and ship each one.
• Collaborate with platform team and forward deployed engineers to integrate with legacy ERPs.

Skills

Full-stack experience

TypeScript

Frontend framework

SQL/Postgres

AI coding tools

Fluent English

Shipping real products

Tools

GitHub

Job description

America's industrial base runs on systems built in the 1980s. Billions of dollars in critical components (F-35 parts, industrial assemblies, electronics, bolts and hoses) still move through email threads, Excel sheets and disconnected ERPs.

We're replacing that with an AI-native platform that makes aerospace, electronics, industrial and defense supply-chain operations nearly autonomous. Faster quoting. Faster procurement. Full visibility. Real operational intelligence for the companies our nation depends on.

Quick facts:

YC W25 company, top 5% growth in batch

Raised $10M+ from investors including Paul Graham, SV Angel, Pear VC and CRV

Team of 20 co-living in our Warsaw & SF Hacker Houses

7-figure ARR, transacting ~$50M a week through our system

The role

Our Full Stack Engineers work with the platform team and our forward deployed engineers to build the systems our customers run on. Most of that work means integrating with legacy ERPs and email-driven workflows that move real orders every day.

Full-time, in person in our Warsaw office. This is not a remote role.

Design, build and maintain features end to end, from schema to UI

Run several projects in parallel and get each one shipped

Up to one week of international travel per quarter (SF HQ or customer sites)

What we're looking for

5+ years of genuine full-stack experience

Absolute grinder. Interested in co-living (though not required)

You've shipped real full-stack products and can show us one: a GitHub repo, a live web app or a Loom walkthrough

You've designed systems on your own, not only built someone else's spec

Strong in TypeScript and at least one frontend framework (React, Svelte, Next, etc.)

Comfortable in SQL, preferably Postgres. You can write, optimise and debug complex queries, not just call an ORM

You use AI coding tools every day and understand where the frontier is

Fluent English, and comfortable working for founders in their early twenties

Comfortable with ambiguity. Priorities can change week to week

Low ego, curious, intellectually honest. Focused on outcomes, not on being right

The process

Initial call with engineer → Technical screening → Quick call with founder → Fly out to SF/Warsaw HQ for onsite (on us) → Offer