Senior ASIC Modeling Software Engineer at Upscale AI – US - Headquarters | Jobyssey

Why join Upscale, Inc.

Upscale, Inc., is building the high-performance infrastructure powering the next generation of artificial intelligence. Backed by over $300M in funding and rapid global adoption, we are scaling systems designed for the world’s most demanding AI workloads.

We focus on first-principles engineering across silicon, systems, and networking—where performance, scale, and execution are critical. Our team is talent-dense and high-performing. We value ownership, technical rigor, and speed, and we offer the opportunity to work on foundational problems with immediate, real-world impact.

If you’re looking to do high-impact work, move fast, and help define the infrastructure behind the future of AI—Upscale is where you can produce meaningful work at the frontier—and operate at a high standard.

Position Overview

About the Role: We're building the simulation platform for UpscaleAI's next-generation AI networking ASICs. The platform is a functionally accurate software model of our ASIC architecture, enabling software development, verification, and customer validation before silicon is available. You'll be responsible for developing, testing and maintaining the platform across multiple ASIC generations, ensuring it accurately represents hardware behavior and scales to support our customers' demanding AI infrastructure workloads.

What You'll Work On:

ASIC Architectural Model: Our current-generation ASIC simulator
Next-gen ASIC models: Future silicon with enhanced AI networking features
Multi-chip simulation: Modeling systems with multiple interconnected ASICs
Performance optimization: Making large-scale simulations practical

Key Responsibilities

Design and implement software model components that accurately simulate ASIC behavior (forwarding engines, schedulers, memory subsystems, control plane interfaces)
Translate architectural specifications and microarchitecture documents into high-fidelity C++ models, ranging from functionally accurate to performance-accurate depending on the subsystem
Develop and maintain the register model, memory map, and configuration interfaces
Implement packet processing pipelines for multiple forwarding modes
Optimize model performance for large-scale simulations
Collaborate with RTL engineers to ensure model-to-silicon correlation
Work with the architecture team to validate algorithm and architectural choices through simulation
Work with SDK and platform software teams to enable software development and validation on the model
Support multiple ASIC versions with maintainable, configurable model architecture

Requirements

7+ years of experience in C/C++ architecture model development, cycle-aware simulation, or ASIC verification
Expert-level C++ programming (modern C++17)
Deep understanding of network switch/router architecture: forwarding tables, scheduling, QoS, ACLs
Experience with packet processing pipelines and dataplane simulation
Familiarity with hardware description languages (Verilog/SystemVerilog) and reading RTL
Experience with gRPC, Protocol Buffers, or similar IPC mechanisms
Experience with C++ unit testing frameworks (e.g., Google Test)
Familiarity with Python for test automation, tooling, and scripting
Strong debugging skills across software and hardware domains

Nice to Have

Experience with AI/ML networking (scale-up fabrics, RDMA, collective operations)
Experience using ns-3 and/or HTSim to model high performance network architectures.
Familiarity with SAI (Switch Abstraction Interface) or SONiC
Experience with FPGA prototyping or emulation platforms
Background in memory subsystem modeling (DDR, HBM, caches)
Experience with configuration-driven simulation frameworks (YAML, JSON, protobuf-based config)

Where you fall within that range depends on your experience, skills, and impact—we benchmark against internal levels to keep things fair and consistent.

Equal Opportunity

Upscale, Inc., is building a team that reflects a wide range of perspectives, backgrounds, and experiences. We’re proud to be an Equal Opportunity Employer and consider all qualified applicants regardless of race, color, religion, national origin, sex, sexual orientation, gender identity, disability, or veteran status.

Accessibility & Accommodations

We’re committed to making our hiring process accessible to everyone. If you need accommodations at any stage, just reach out to us at [email protected]—we’re happy to help. Note: This inbox is only for accommodation requests.

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Why join Upscale, Inc.

Key Responsibilities