Senior Python Security Engineer — Encryption & PHI

Stack AI, Inc.; Warszawa; Hybrid; PLN 260,000 - 380,000; Full time

Job summary

StackAI is seeking a senior Python engineer to join the Core Engineering team. You will build security-critical product systems that encrypt customer data, manage keys and signatures, and enforce tenant boundaries across hosted, VPC, and on-prem deployments.

The role requires hands-on backend work, securing credentials, protecting PHI/PII, and shaping trusted product boundaries with architecture and implementation focus. You’ll lead migrations and safe rollouts in a fast-moving codebase.

Qualifications

• 4+ years of experience building and operating production backend systems.
• Strong professional experience with Python in a substantial production codebase.
• Hands-on experience implementing and operating security-critical product systems, including the code that enforces their guarantees.
• Depth in at least one of Encryption & key management, signing/auth, sessions or token infrastructure, multi-tenant isolation, sensitive-data processing, or secure storage of credentials.

Responsibilities

• Build encryption and key-management systems across hosted, VPC, and on-prem deployments.
• Protect PHI, PII, and other sensitive data across workflows, logs, and storage.
• Secure customer credentials from storage to runtime usage.
• Strengthen tenant isolation, signing/verification, and token handling.
• Create shared security foundations with Python services, libraries, and APIs.
• Evolve live systems safely with migrations, rollouts, observability, and rollback.

Skills

Python backend

Security-critical systems

Encryption and key mgmt

Multi-tenant isolation

Data privacy & PHI/PII

Trust boundary design

Tools

HashiCorp Vault

Cloud KMS

HSMs

Job description

StackAI is seeking a senior Python engineer to join the Core Engineering team. You will build security-critical product systems that encrypt customer data, manage keys and signatures, and enforce tenant boundaries across hosted, VPC, and on-prem deployments.

The role requires hands-on backend work, securing credentials, protecting PHI/PII, and shaping trusted product boundaries with architecture and implementation focus. You’ll lead migrations and safe rollouts in a fast-moving codebase.