RDMA Performance engineer

Codilime; Warszawa; Remote; PLN 120,000 - 170,000; Full time

Benefits offered by this job

Flexible work arrangements

Training budget

Job summary

CodiLime is looking for an RDMA Performance Engineer to join the project team working on SONiC validation on NVIDIA Spectrum-Based Platforms for AI Networking. You will configure, troubleshoot and optimize data center fabrics to achieve maximum throughput and minimal latency.

You should have extensive experience with network engineering, RDMA, NCCL, RoCEv2, PFC and ECN, and a hands-on track record with NVIDIA/Mellanox Spectrum switches and ConnectX NICs.

Qualifications

• 7+ years of professional experience in network engineering, with preferably 3+ years specifically focused on data center network design and architecture.
• Hands-on experience configuring and troubleshooting core network protocols and technologies, including BGP, EVPN/VXLAN, LACP, and ECMP.
• Deep understanding of AI-dedicated data center designs, including Rail-Optimized Design (ROD) and Rail-Unified Design (RUD) topologies.
• Proven experience configuring, managing, and troubleshooting NVIDIA/Mellanox Spectrum switches and ConnectX Network Interface Cards (NICs).
• Deep understanding of the protocols and congestion control mechanisms required for AI-dedicated data centers, specifically RoCEv2, Priority-based Flow Control (PFC), and Explicit Congestion Notification (ECN).
• Demonstrated ability to tune and optimize network environments, with specific focus on switch buffer tuning and the implementation of Quality of Service (QoS) policies.
• Experience conducting performance benchmarking and validation for AI-ready data center fabrics utilizing RDMA and the NVIDIA Collective Communication Library (NCCL).
• Demonstrated ability to leverage AI agents/tools to automate tasks, testing, and analysis
• Strong technical documentation skills and professional English communication
• Nice-to-have certifications (CCNP/CCIE Enterprise/DC, JNCIP) and exposure to CI/CD and IaC concepts

Responsibilities

• Configure, troubleshoot, and maintain NVIDIA/Mellanox Spectrum switches and ConnectX NICs.
• Implement and tune congestion control for AI workloads: RoCEv2, PFC, ECN.
• Optimize networks for maximum throughput, low latency, and minimal JCT via setup tuning.
• Perform performance benchmarking and validation on AI-ready data center fabrics using RDMA and NCCL.
• Leverage AI agents/tools to automate routine tasks, testing, and analysis.
• Author and maintain clear technical documentation detailing designs, configurations, and benchmarks.

Skills

Network design

BGP

EVPN/VXLAN

LACP/ECMP

RoCEv2

PFC

ECN

RDMA

NCCL

QoS

English communication

Tools

pyATS

NAPALM

Batfish

Nornir

NetBox

GitLab CI

GitHub Actions

Jenkins

Job description

Get to know us better

CodiLime is a software and network engineering industry expert and the first-choice service partner for top global networking hardware providers, software providers and telecoms. We create proofs-of-concept, help our clients build new products, nurture existing ones and provide services in production environments. Our clients include both tech startups and big players in various industries and geographic locations (US, Japan, Israel, Europe).

While no longer a startup - we have 250+ people on board and have been operating since 2011 we’ve kept our people-oriented culture. Our values are simple:

• Actto deliver.

• Disruptto grow.

• Team upto win.

The project and the team

The project involves SONiC validation on NVIDIA Spectrum-Based Platforms for AI Networking.

What else you should know:

• We use Agile methodology.

• The team operates within a startup environment.

• The client is based in the US.

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

Your role

As a part of the project team, you will be responsible for:

• Configure, troubleshoot, and maintain NVIDIA/Mellanox Spectrum switches and ConnectX Network Interface Cards (NICs).

• Implement and tune advanced congestion control mechanisms essential for AI workloads, including RoCEv2, Priority-based Flow Control (PFC), and Explicit Congestion Notification (ECN).

• Optimize network environments to ensure maximum throughput, minimal latency, and minimal Job Completion Time (JCT) by performing setup tuning.

• Conduct extensive performance benchmarking and validation testing on AI-ready data center fabrics utilizing RDMA and the NVIDIA Collective Communication Library (NCCL).

• Leverage AI agents and specialized tools to automate routine network tasks, conduct rigorous testing, and analyze network telemetry.

• Author and maintain clear, high-quality technical documentation detailing network designs, configurations, and benchmarking results.

Do we have a match?

As a RDMA Performance engineer you must meet the following criteria:

• 7+ years of professional experiencein network engineering, with preferably 3+ years specifically focused on data center network design and architecture.

• Hands‑on experience configuring and troubleshooting core network protocols and technologies, including BGP, EVPN/VXLAN, LACP, and ECMP.

• Deep understanding of AI-dedicated data center designs, including Rail-Optimized Design (ROD) and Rail-Unified Design (RUD) topologies, coupled with practical, hands‑on experience configuring and deploying them.

• Proven experience configuring, managing, and troubleshooting NVIDIA/Mellanox Spectrum switches and ConnectX Network Interface Cards (NICs).

• Deep understanding of the protocols and congestion control mechanisms required for AI-dedicated data centers, specifically RoCEv2, Priority-based Flow Control (PFC), and Explicit Congestion Notification (ECN).

• Demonstrated ability to tune and optimize network environments, with specific focus on switch buffer tuning and the implementation of Quality of Service (QoS) policies.

• Experience conducting performance benchmarking and validation for AI-ready data center fabrics utilizing RDMA and the NVIDIA Collective Communication Library (NCCL).

• Demonstrated ability to leverage AI agents/tools to automate tasks, testing, and analysis

• Strong technical documentation skills and professional English communication

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

• Professional-level certifications (CCNP/CCIE Enterprise/DC, JNCIP or equivalent)

• Hands‑on experience with network automation & validation frameworks (pyATS, NAPALM, Batfish, Nornir, NetBox)

• Exposure to CI/CD pipelines (GitLab CI, GitHub Actions, Jenkins) and IaC concepts

More reasons to join us

• Flexible working hours and approach to work: fully remotely, in the office or hybrid

• Professional growth supported by internal training sessions and a training budget

• Solid onboarding with a hands‑on approach to give you an easy start

• A great atmosphere among professionals who are passionate about their work

• The ability to change the project you work on