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Mid/Senior Software Engineer – Network & Security Focus @ CodiLime
  • Warsaw
Mid/Senior Software Engineer – Network & Security Focus @ CodiLime
Warszawa, Warsaw, Masovian Voivodeship, Polska
CodiLime
21. 10. 2025
Informacje o stanowisku

The project and the team

The goal of the project is to develop core network and security features close to the kernel and network stack. About half of the tasks are in C/C++ for low-level modules, and the other half in Python for automation, tooling, and integration.

The project involves close collaboration with a team from our client. It is globally distributed, with members in the USA and India - and now, a new team of software engineers is joining in Poland. 


We work on multiple interesting projects at the time, so we may invite you to the interview for another project if we see that your competencies and profile are well suited for it.



    Do we have a match?

    As a Software Engineer, you must meet the following criteria:

    • Strong programming skills, with approximately 50% in C/C++ and 50% in Python
    • Solid foundation in computer networks: IP, TCP/UDP, routing, NAT, proxy patterns
    • Deep understanding of firewall/security systems: packet filtering, stateful firewalls, URL filtering, IPS/IDS
    • Experience debugging tricky traffic flows (traffic goes forward but reply doesn’t return)
    • Ability to implement or consume proxy, inspection, HTTP/HTTPS parsing
    • Experience with kernel-level or system-level network hooks/modules (Linux netfilter, packet sockets)
    • Good command of English (B2 level or higher)

    Beyond the criteria above, we would appreciate the nice-to-haves:

    • Experience with firewall vendor software (iptables, nftables, Palo Alto, Fortinet, Cisco ASA)
    • Familiarity with SSL/TLS termination and proxy SSL inspection
    • Knowledge of IDS/IPS systems (Snort, Suricata)
    • Experience in high-performance networking systems
    • Familiarity with container/virtualization networking
    • Exposure to distributed or scalable systems

    The project and the team

    The goal of the project is to develop core network and security features close to the kernel and network stack. About half of the tasks are in C/C++ for low-level modules, and the other half in Python for automation, tooling, and integration.

    The project involves close collaboration with a team from our client. It is globally distributed, with members in the USA and India - and now, a new team of software engineers is joining in Poland. 


    We work on multiple interesting projects at the time, so we may invite you to the interview for another project if we see that your competencies and profile are well suited for it.


      ,[Designing, implementing, and maintaining network/security features (firewall, NAT, proxy, intrusion prevention, filtering), Integrating with kernel or low-level modules (netfilter, packet capture/forwarding logic), Building advanced traffic inspection and filtering logic (URL filtering, protocol analysis, deep packet inspection), Troubleshooting complex network failures (asymmetrical routing, NAT/firewall interactions, dropped reply traffic), Collaborating with architects, QA, and other engineers on secure network systems, Reading and applying protocol & security specs (IP, TCP, HTTP, SSL/TLS), Ensuring performance, security, and robustness in production environments Requirements: C, C++, Python, TCP, UDP, Proxy, IPS/IDS, HTTP, Linux, iptables, nftables, SSL, TLS, Virtualization Tools: Agile. Additionally: Sport subscription, Training budget, Private healthcare, Flat structure, Small teams, International projects, Masterclazz training, Free coffee, Bike parking, Playroom, Free beverages, Free lunch, In-house trainings, Modern office, No dress code.

    • Praca Warszawa
    • Chief security officer Warszawa
    • Warszawa - Oferty pracy w okolicznych lokalizacjach


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