10/18/2026 updated

**** ******** ****
40 % partially available

Senior C/C++ Telecom Engineer & AI-Agent Tooling Specialist

Gdansk, Poland
Only remote
MSc Eng. in Telecommunications, Gdańsk University of Technology
Gdansk, Poland
Only remote
MSc Eng. in Telecommunications, Gdańsk University of Technology

Profile attachments

CV_Marek_Wlizlo.pdf

About me

Senior C/C++ Linux engineer (20+ years) in real-time telecom and embedded systems: SIP/RTP media stacks, codecs, radio gateways, Conan 2 and GitLab CI. Available part-time, about 20 h/week, fully remote in CET, alongside a permanent role. Fixed-scope, well-defined work preferred.

Clean Code Principles3GPP (Telecommunication)VoIPC++ (Programming Language)CMakeCodecsEmbedded CEmbedded SystemsLinux On Embedded SystemsEmbedded SoftwareSession Initiation ProtocolsPython (Programming Language)TCP/IPWebRTCReal-Time Transport ProtocolGitlab-ciDocker
C/C++ Software Development for Telecom & Embedded Systems
Over 20 years of experience in C/C++ software development with a focus on real-time telecommunication and embedded Linux systems. Deep expertise in 3GPP mission-critical push-to-talk (MCPTT/MCX), SIP/RTP media stacks, and radio gateways (TETRA, DMR, NXDN) for public-safety and energy customers. Proficiency in C++17 with STL, Boost, and multithreading, as well as C, Python 3, Bash, and JavaScript/TypeScript.

Build, DevOps & CI/CD Engineering
Ownership of the full C++ delivery chain end to end using Conan 2, GitLab CI quality gates, multi-arch container images, and Kubernetes CI. Expertise in CMake, SonarQube (sonar-cxx), clang-tidy, cppcheck, gcovr, Trivy, Docker/Kaniko, distroless multi-arch images, Docker Swarm, Kubernetes (RKE2/K3s), Artifactory, Keycloak, Prometheus/Grafana, Buildroot, and Debian packaging for ARM, Android NDK, and iOS.

AI-Agent Tooling & LLM Pipeline Engineering
Since 2025, building AI-agent tooling for engineering teams using Claude Code skills, hooks, MCP integrations, and RAG over 3GPP and vendor documentation. Authoring of 15 Claude Code skills covering release automation, Jira and time tracking, Conan and quality-gate migrations, agent-driven hardware test rigs, and a fail-closed hook enforcing Jira content quality. Production LLM pipelines with verification using FastAPI, PostgreSQL, Next.js, Anthropic API, BAML, BM25 RAG, and GitHub Spec Kit.

Telecom Protocols & Standards
Comprehensive knowledge of SIP, SDP, RTP/RTCP, H.323, MGCP, SCCP, XCAP, WebRTC, 3GPP MCPTT/MCX (TS 24.379, 24.380, 24.381, 29.380, 23.283), ETSI TS 103 564 plugtests, lawful interception, and TR-069.

Radio Technologies & Codecs
Hands-on experience with TETRA (PEI/AT, SDS-TL, LIP), DMR/MOTOTRBO (IPSC, XCMP/XNL), NXDN NXIP, Dimetra CADI/MultiCADI, AMBE (DVSI), AMR-WB/NB, G.729, TETRA-ACELP, Opus, H.264/H.265/VP8, and ALSA audio tuning on embedded Linux.

Libraries & Frameworks
Practical use of resiprocate, Kamailio, RTPProxy, OpenSIPS, oRTP/mediastreamer2, gRPC/protobuf, libevent, websocketpp, gSOAP, Qpid, spandsp, and GoogleTest/GMock for telecom and embedded software development.

Software Architecture & Design Patterns
Application of OOP/OOD, DDD, state machines, ports and adapters, Clean Code principles, and spec-driven development for complex software architectures in large C++ codebases.

Technical Leadership & Mentoring
Former R&D team leader with experience leading teams of C++/Linux software engineers. Mentoring, code reviews, Polish-language changelogs with root-cause analysis for customers, and promotion of Clean Code practices and spec-driven development across engineering teams.

Machine Learning & TensorFlow Lite
Practical experience with CNN model quantization to INT8 using TensorFlow Lite for embedded targets (ESP32-S3), direction-of-arrival algorithms (MUSIC, GCC-PHAT), and TinyML deployment for acoustic drone detection.

Experience

Professional experience10+ years
Freelancer since2026

Languages

GermanBasic knowledgeEnglishFluentPolishNative speaker

Project history

AI Engineer / Developer

Personal Project (Dawk AI)
Multi-agent LLM pipeline extracting medication dosing from official product characteristics: seven cooperating agents (Anthropic API, BAML), literal-match judge, source-span verifier against hallucination, publication gate, golden set, per-agent cost tracking, Prometheus alerting. Built with Python 3.12, FastAPI, PostgreSQL, Next.js; ~52k lines.

ML Engineer / Developer

Personal Project (hexloop-lab)
Acoustic drone detection using CNN (~30k parameters) quantised to INT8 TensorFlow Lite (24 KB) for ESP32-S3, achieving F1 = 0.956 on ESC-50 + DroneAudioDataset. Implemented direction of arrival algorithms (MUSIC, GCC-PHAT), live demo, and pre-PoC investor report.

C/C++ Software Engineer, R&D Radio Systems Department

DGT Sp. z o.o. (previously DGT LAB S.A.)
Principal author of the MCPTT/MCX media-plane library implementing floor control per TS 24.380/24.381 with ~450 unit tests. Developed Interworking Function (IWF) between MCPTT and LMR per TS 29.380/23.283 with ~600 unit and 3GPP-compliance tests. Maintained RTP/RTCP media stack across five library layers. Integrated radio gateways and vendor APIs (Motorola TETRA, Dimetra, Kenwood NXDN, DVSI AMBE). Built radio emulator and hardware-in-the-loop test rigs. Developed native MCPTT client core (C++17, gRPC) for Android NDK/JNI, iOS, and Windows. Migrated ~20 repositories to Conan 2.x, authored GitLab CI templates, and rolled out quality gates. Authored 15 Claude Code AI-agent skills for engineering automation. Mentored team members and promoted Clean Code practices.

C/C++ Software Engineer, R&D M2M Department

DGT Sp. z o.o. (previously DGT LAB S.A.)
Specialized in design and programming of advanced solutions for embedded systems on Linux platforms using C, C++, and Bash scripting. Developed software for energy devices at transformer substations. Implemented communication features for data exchange with core network servers using IP packet technology over cellular networks. Developed an embedded web server using JavaScript and HTML for remote device management. Implemented TR-069 protocol support for supervision, monitoring, and software updating. Contributed to DGT M2M solutions including web interface development using GoAhead web server.

Team Leader, R&D VoIP/NGN Department

DGT Sp. z o.o. (previously DGT LAB S.A.)
Led a team of six C++/Linux software engineers responsible for strategic DGT product lines in the VoIP and NGN domain. Managed the full development lifecycle (design, implementation, testing, deployment, maintenance) for PVoIP gateways and the Lawful Interception system. Ensured high code quality, timely delivery, and effective team collaboration. Responsible for the successful delivery and deployment of the DGT IP LI (Lawful Interception) system for Orange Poland.

C/C++ Software Engineer

DGT Sp. z o.o. (previously DGT LAB S.A.)
Key developer for the radio control application (msrip) within the DGT MCS IP dispatch system deployed for major Polish emergency and public safety services. Implemented integration with Motorola DMR & TETRA radio APIs. Designed and implemented H.323 & modem AT-Hayes signalling gateways for DGT PVoIP solution used by the Polish Army in international missions. Developed SIP soft-phone software for an embedded Linux platform in DGT VDSL2 CPE gateway deployed by Orange Poland. Implemented core functionalities for real-time media stream processing and developed E1 RAS server software.

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