PCactus is a software development company, providing full-cycle services for the European market. More than 170 companies increased business productivity using solutions developed by Cactus experts. The company has been regularly included in the listings of the best software development companies in Belgium and Europe. /ppbr/ppThis position is based in Spain, and you will collaborate with teams across Europe and an international partnership landscape. /ppbr/ppbWhat You Will Do /b /pulliDesign and implement high-performance packet I/O pipelines using DPDK or equivalent frameworks. /liliAdapt existing UDP application code to work with NIC queue–driven RX/TX loops, batch processing, and hardware offloads. /liliConfigure and tune Linux servers for ultra-low latency: hugepages, NUMA awareness, CPU pinning, NIC driver binding, RSS/flow steering. /liliEnsure reliable operation at very high packet rates; instrument detailed throughput, latency, and packet-loss metrics. /liliCollaborate with the application team to integrate kernel-bypass transport with existing processing pipelines. /liliStay current with RDMA and user-space networking trends (DPDK, netmap, AF_XDP, eBPF/XDP) to evaluate trade-offs. /li /ulpbr/ppbWhat We Expect /b /pulliExpert C/C++ in performance-critical networking code. /liliHands-on experience with DPDK or similar (AF_XDP, netmap, PF_RING) in production systems. /liliStrong knowledge of Linux performance tuning and NIC hardware features (RSS, flow steering, checksum/jumbo offloads). /liliFamiliarity with RDMA (RoCE, InfiniBand, iWARP) concepts and when to use them vs. raw packet I/O. /liliExperience with packet capture/analysis tools (tcpdump, Wireshark, perf). /liliStrong problem-solving and debugging skills at the network + OS boundary. /liliExcellent English communication skills – written and spoken. /li /ulpbr/pp*Preferred industry backgrounds: /pulliHigh-frequency trading (HFT) / fintech — ultra-low-latency networking engineers. /liliTelecom / 5G / packet core — engineers building EPC, UPF, or fronthaul solutions. /liliNetwork security DPI appliances — intrusion detection/firewall data plane developers. /liliCDN / video streaming / media transport — high-performance transport engineers. /liliHPC / storage networking — experience with RDMA, NVMe-oF, or cluster interconnects. /li /ulpbr/ppbWhat We Offer /b /pulliWorking with international clients. /liliAn environment to develop your professional capabilities and take ownership. /liliCollaboration with a team of open, dynamic, and international experts. /liliFull-time position with a competitive salary and benefits, including learning opportunities. /liliFlexible working hours. /liliGet-together team events. /li /ul