Python Software Engineer (Cybersecurity)

Last updated on November 7, 2026

Join Rublon and work with a team of cybersecurity enthusiasts building the future of enterprise user authentication.

Rublon MFA is a multi-factor authentication platform used by customers in more than 60 countries to protect employee logins to networks, servers, and applications. Besides our cloud services, we build components that run in our customers’ networks and connect Rublon MFA with VPNs, firewalls, directories, and security systems.

We are looking for a Regular Python Software Engineer with several years of backend experience who wants to work on network authentication and security integrations.

What You’ll Work On

You will develop two Rublon products that bring MFA and security monitoring into enterprise networks:

• Rublon Authentication Proxy: a RADIUS and LDAP proxy that adds MFA to VPNs, firewalls, and any other service that supports RADIUS or LDAP authentication. It works with Active Directory, OpenLDAP, FreeIPA, Google Secure LDAP, Microsoft Entra ID, and existing RADIUS servers, and runs on Linux and Windows Server.
• Rublon Log Sync: a service that continuously exports audit, authentication, and activity logs from Rublon MFA to SIEM systems in JSON or CEF format.

Both products handle security-critical traffic, so reliability, performance, and secure protocol handling matter in every change. We keep developing them and the services around them, and we want them to run just as well at large scale, in customer networks and in the cloud. We pick the best language for each component: today we mostly use Python, and some new components may be written in Go or Rust.

We work with AI-assisted development and Agentic Engineering. Tools such as Claude Code are standard in our daily work: we use them for planning, implementation, testing, code review, and documentation, while staying fully responsible for the quality, security, and correctness of the code.

This is a pure backend engineering role. No frontend development experience is required.

How You’ll Work

• Employment contract: full-time at our office in Kraków or Zielona Góra (no remote work)
• B2B contract: 100% remote from anywhere in Poland
• Technology stack: Python 3, RADIUS, RadSec, LDAP and LDAPS, TLS and mTLS, x.509 certificates, Active Directory, OpenLDAP, FreeIPA, Microsoft Entra ID and Microsoft Graph, Linux (systemd), Windows Server, Inno Setup, CEF, syslog and JSON, SIEM integrations, GitHub CI/CD, AI coding agents (e.g. Claude Code)
• Language: Polish in the team’s daily work
• Self-development: access to online training courses and sponsored certifications
• Benefits: private medical care and MultiSport card

What You’ll Do

As a Python Software Engineer at Rublon, you will:

• Develop and maintain Rublon Authentication Proxy and Rublon Log Sync
• Implement RADIUS and LDAP protocol features, such as authentication modes, request proxying, and RadSec
• Build and extend integrations with Active Directory, OpenLDAP, FreeIPA, Google Secure LDAP, Microsoft Entra ID, and other RADIUS servers
• Develop Directory Sync, which synchronizes users and groups from Active Directory and OpenLDAP to Rublon MFA
• Build reliable log delivery to SIEM systems, with checkpoints, retries, and correct CEF, syslog, and JSON output
• Harden network-facing code: TLS and mTLS, certificate validation, secrets handling, and protection against attacks such as Blast-RADIUS
• Improve performance, concurrency, and resource usage so our services handle many logins at the same time
• Add observability: structured logging, metrics, and diagnostics that help our support team and our customers
• Build and maintain packages and installers for Linux (systemd) and Windows Server
• Test integrations with VPNs, firewalls, directory services, and SIEM platforms
• Implement features within the agreed architecture and propose improvements
• Use AI coding agents (e.g. Claude Code) in your daily work and critically review their output
• Take part in code reviews and share knowledge with the team
• Work with product managers, QA, support, and cybersecurity specialists on product development

Skills You Have

• At least 3 years of commercial experience developing backend software in Python
• Good knowledge of networking fundamentals: TCP/IP, UDP, DNS, and TLS
• Practical knowledge of RADIUS or LDAP at the protocol level, not only at the configuration level
• Experience with Active Directory or other LDAP directories
• Experience with concurrency in Python (asyncio, threads, or processes)
• Understanding of secure coding for network services, including handling untrusted input and secrets
• Experience running and debugging services on Linux
• Experience with automated testing and CI/CD, preferably GitHub-based pipelines
• Practical experience developing software with AI tools such as Claude Code
• The ability to work independently and explain your technical decisions clearly
• Fluent Polish (C1)
• English good enough to read technical documentation and RFCs (B1; fluent English is not required)

Nice To Have

Experience with any of the following will be a strong advantage:

• Go or Rust, ideally in network services
• RadSec, EAP methods, and 802.1X
• x.509 certificates, PKI, and certificate-based authentication
• FreeRADIUS, Microsoft NPS, or other RADIUS servers
• Microsoft Entra ID and Microsoft Graph API
• SIEM platforms such as Microsoft Sentinel, Splunk, Elastic, Graylog, or Wazuh
• Multi-tenant SaaS services that scale horizontally
• Docker, Kubernetes, and AWS
• Monitoring, metrics, and tracing (e.g. Prometheus, OpenTelemetry)
• Services and installers for Windows Server
• VPN gateways, firewalls, and other network devices
• AWS or security certifications
• Formal education in Information Security, Cybersecurity, Computer Science, or a related field, or equivalent professional experience

Why Apply

This role may be a strong fit if:

• You want to build security software that protects network access for customers in more than 60 countries
• You like working close to protocols such as RADIUS, LDAP, TLS, and syslog
• You enjoy building reliable services that run in real customer networks
• You want to help shape how these products run at scale, in customer networks and in the cloud
• You want to work with Python today and use Go or Rust for new components
• You use AI coding agents every day and want a team that treats them as a standard tool
• You prefer backend engineering and do not want a frontend-focused role
• You value secure coding, automation, observability, and long-term maintainability

Steps After You Apply

1. You’ll be invited to an online meeting with our recruiter
2. Afterwards, we’ll ask you to complete a small assignment, which you’ll then discuss with one of our technical leads
3. Finally, we’ll invite you to a final interview and, if everything goes well, make you an offer