Senior Software Engineer

StepTo; Time; Remote; NOK 637,000 - 955,000; Full time

Benefits offered by this job

Remote-first (Serbia) with optional Be

Top-of-market EUR salary

€1,500/year learning budget

25 days PTO

Flexible hours

Culture respects time outside work

Job summary

StepTo is seeking a Senior Software Engineer to join a small, hands-on team building enterprise AI infrastructure for financial institutions. You’ll own end-to-end product and infrastructure work, shipping features from design to deployment on a Python/FastAPI backend that talks to PostgreSQL.

Remote-first in Serbia, with a focus on initiative, speed, and ownership. We offer top-of-market EUR salary, a €1,500/year learning budget, and 25 days PTO, plus flexible hours and a culture that respects

Qualifications

• Strong production Python development experience, backend services and APIs (FastAPI preferred).
• Solid PostgreSQL expertise: schema and data modeling, SQL, indexing, query planning, transaction behavior, and performance tuning.
• Systems engineering fundamentals: Linux/server environments, networking basics, concurrency, resource utilization, reliability, profiling, and debugging.
• Sound software architecture and engineering judgment: maintainable code, testing, observability, deployment, and scalability.
• End-to-end ownership: independently scope, implement, validate, and ship features.
• Clear communication and comfort working directly with founders.
• Practical, effective use of AI coding tools (Claude Code, Codex, or similar), with strong review and verification habits.
• Comfortable with ambiguity, startup mentality, initiative, and accountability.

Responsibilities

• Build and optimize a Python/FastAPI backend that interacts efficiently and reliably with PostgreSQL.
• Independently scope, implement, validate, and ship features from design through testing and deployment.
• Diagnose performance bottlenecks across the application, database, and server environment, and fix them at the root.
• Make sound architecture decisions that keep the codebase maintainable, observable, and scalable.
• Work directly with technical founders to turn ambiguous problems into simple, robust solutions.
• Use AI coding tools (Claude Code, Codex, or similar) effectively, backed by strong review and verification habits.
• Proactively identify improvements to the product, the infrastructure, and the way the team ships.

Skills

Python backend

FastAPI

PostgreSQL

System design

Linux

Performance optimization

AI tooling

End-to-end ownership

Communication with founders

Kubernetes

Tools

Claude Code

Codex

SQL tooling

Job description

• Remote
• Full-time

About The Role

We're looking for a high-agency, self-directed Senior Software Engineer with excellent engineering fundamentals to join a small, hands‑on team building enterprise AI infrastructure for financial institutions. You'll own meaningful product and infrastructure work end to end, collaborate directly with technical founders, and ship quickly.

The primary work is building and optimizing a Python/FastAPI backend that interacts efficiently and reliably with PostgreSQL. You should be able to reason about systems, diagnose bottlenecks, make sound architecture decisions, and deliver complete features from design through testing and deployment.

We value initiative, curiosity, speed, accountability, and a startup mentality over titles or years of experience. You should be comfortable with ambiguity, proactively identify improvements, and favor simple, robust solutions.

What You'll Do

• Build and optimize a Python/FastAPI backend that interacts efficiently and reliably with PostgreSQL.
• Independently scope, implement, validate, and ship features from design through testing and deployment.
• Diagnose performance bottlenecks across the application, database, and server environment, and fix them at the root.
• Make sound architecture decisions that keep the codebase maintainable, observable, and scalable.
• Work directly with technical founders to turn ambiguous problems into simple, robust solutions.
• Use AI coding tools (Claude Code, Codex, or similar) effectively, backed by strong review and verification habits.
• Proactively identify improvements to the product, the infrastructure, and the way the team ships.

What We're Looking For

• Strong production Python development experience, including backend services and APIs (FastAPI preferred).
• Solid PostgreSQL expertise: schema and data modeling, SQL, indexing, query planning, transaction behavior, and performance tuning.
• Systems engineering fundamentals: Linux/server environments, networking basics, concurrency, resource utilization, reliability, profiling, and debugging.
• Sound software architecture and engineering judgment: maintainable code, testing, observability, deployment, and scalability.
• End-to-end ownership: able to independently scope, implement, validate, and ship features.
• Clear communication and comfort working directly with founders.
• Practical, effective use of AI coding tools (Claude Code, Codex, or similar), with strong review and verification habits.
• Comfortable with ambiguity, with a startup mentality, initiative, and accountability.
• Nice to have: experience with Model Context Protocol (MCP), AI agents, agent observability/tracing, or AI memory systems.
• Nice to have: Kubernetes, containers, cloud infrastructure, or infrastructure automation.
• Nice to have: Go (used in parts of the CLI tooling).
• Nice to have: frontend engineering with React and TypeScript, and Node.js familiarity.

What We Offer

• Remote-first: work from anywhere in Serbia. The Belgrade office is optional.
• You'll work alongside engineers with 5–15 years of experience. No babysitting, just craft.
• Top-of-market salary for Serbia, paid in EUR, reviewed annually and tied to your impact.
• €1,500/year learning budget for conferences, courses, and books.
• 25 days PTO, flexible hours, and a culture that respects your time outside work.