Backend Software Engineer Senior/Staff

DualEntry; Remote; PLN 399,000 - 636,000; Full time

Job summary

A cutting-edge AI startup is seeking a Senior/Staff Backend Software Engineer to design and build core backend systems in Python. You'll take ownership of launching production-ready features while managing complex accounting logic. With 5+ years of experience and a proficiency in modern web frameworks, you'll thrive in a fast-paced, remote-first environment. The role offers a competitive salary ranging from $110K to $175K, along with equity and numerous benefits including 15 PTO days and visa sponsorship for relocation.

Benefits

Equity ownership

15 PTO days

Visa sponsorship option for relocation

Qualifications

• 5+ years of experience in backend engineering.
• Deep experience with complex business logic products.
• Proficient in Python and a modern web framework.

Responsibilities

• Design and build core backend systems using Python.
• Build APIs, services, and infrastructure for accounting logic.
• Launch production-ready features and manage complexity.

Skills

Backend engineering

Complex business logic products

Python programming

API development

CI/CD processes

English (C1+)

Tools

AWS

FastAPI

Flask

Django

Job description

Backend Software Engineer (Senior/Staff) @ DualEntry
Warszawa
Warsaw, Masovian Voivodeship, Polska

We’re building the first true AI‑powered accounting product. If you’re excited to build systems that power AI and build the first true accounting AI product with your own hands, we’d love to hear from you.

About DualEntry

Founded in 2024, DualEntry is one of NYC’s fastest‑growing AI startups. Our AI‑native ERP lets teams achieve more in less time. $5M‑ARR businesses and NYSE‑listed companies trust us to automate busywork and fuel growth with powerful reporting and insights. We’re making the one‑person finance team a reality and putting legacy ERPs from the 1990s in the past. We operate with urgency, ownership, and speed.

Why This Role Matters Now

Since launching 18 months ago, we’ve raised $100M with backing from Lightspeed, Khosla, and Google Ventures. We’ve accelerated by hiring top talent, and we’re growing our team to drive momentum. This intense, hands‑on role has full ownership and will shape the product, customers, and trajectory at an early and defining moment.

Where You’ll Create Impact

• Design and build core backend systems using Python
• Build APIs, services, and infrastructure that handle real‑time, business‑critical, and complex accounting logic
• Launch production‑ready features from scratch, including CI/CD pipelines and deployment
• Work with product to turn complex finance workflows into performant, secure systems
• Manage complexity in a business‑logic‑heavy product, including data migrations and scale challenges
• Integrate third‑party tools and external systems — proactively managing edge cases and risk
• Own your work from architecture to testing, monitoring, and post‑release care

What Sets You Up for Success

• 5+ years of experience in backend engineering
• Deep experience with complex business logic products
• Proficient in Python and a modern web framework (FastAPI, Flask, or Django)
• Experience deploying on AWS (or similar cloud infrastructure)
• Experience building and testing robust APIs
• Solid understanding of software lifecycle, CI/CD, and production‑readiness
• Ability to manage complex systems with evolving requirements
• Fluent in English (C1+) with strong written and verbal communication

How You Operate

• Pragmatic: you like to move forward and make decisions based on reality (not theory). We don’t debate if Cassandra has the most theoretical scalability — we use Postgres until it breaks.
• Hard working: "You can work long, hard, or smart, but here you can’t choose two out of three" – Jeff Bezos. We wrote this job post during the weekend.
• Curious: you love to learn, are highly curious about new frameworks and solutions to engineering problems.
• Fast‑moving — you deploy daily, iterate quickly, and never wait for permission.

Why You’ll Thrive Here

• Significant equity ownership in one of the top AI companies in the world
• You’re joining early and will grow with DualEntry
• Your feedback shapes the product directly
• High‑speed culture
• High‑trust environment with high expectations
• Ambitious mission
• Equity: ~$50K+ USD
• Remote‑first team – the fastest team you will have ever worked with
• 15 PTO days + 12 public holidays
• Visa sponsorship option for relocation to NYC within 2 years
• Freedom, autonomy, and impact from day one

Compensation & Benefits

• Base salary: $110K–$175K USD
• Equity: ~$50K+ USD
• B2B contract (regular employment contract available)
• Remote‑first team – the fastest team you will have ever worked with
• 15 PTO days + 12 public holidays
• Visa sponsorship option for relocation to NYC within 2 years
• Freedom, autonomy, and impact from day one