Digital Verification Engineer
Location: Santa Clara, CA
Ladder: Silicon / Hardware Design
Travel: Minimal (0–10%)
Role Overview
At Nexthop AI, the correctness of our digital logic is non-negotiable — a single functional escape in an FPGA or ASIC can compromise an entire switching platform once it ships. We are looking for a Digital Verification Engineer to own the verification environments and test suites that prove our digital subsystems behave exactly as designed. Sitting within the Hardware Design organization, you'll work shoulder-to-shoulder with RTL designers and firmware engineers to catch bugs in simulation — long before they reach silicon, a board, or a customer's rack.
Key Responsibilities
1. Verification Environment Ownership
- Own the testbench: Design, build, and maintain the verification environments for our digital subsystems — from block level through full-chip / subsystem integration — for both FPGA and ASIC targets.
- Reusable methodology: Establish and evolve reusable verification components (drivers, monitors, scoreboards, checkers) so new blocks plug into a consistent, maintainable framework instead of one-off testbenches.
- Reference modeling: Develop behavioral / reference models where needed to independently predict expected DUT behavior and catch discrepancies automatically.
2. Test Development & Coverage
- Test suites: Author directed and constrained-random tests that exercise functional modes, corner cases, error injection, and reset / clock-domain behavior.
- Coverage-driven closure: Define functional and code-coverage goals and drive them to closure — identifying coverage holes and writing the stimulus to fill them.
- Assertions: Embed assertions (SVA) to catch protocol and interface violations at the source, close to where they occur.
3. Simulation, Debug & Regression
- Logic simulation: Run and debug simulations using Modelsim / Questasim and NC-Verilog; triage failures to root cause and partner with RTL designers on the fix.
- Regression: Stand up and maintain automated regression suites — keeping them fast, deterministic, and green so the team gets rapid feedback on every RTL change.
- Waveform debug: Debug efficiently at the waveform level and produce clear, reproducible failure reports that shorten the design–debug loop.
4. System Bring-up & HW/SW Co-validation
- Bring-up support: Support lab bring-up of FPGAs and boards, correlating pre-silicon simulation behavior against real hardware.
- Software collaboration: Partner with firmware / software engineers during system bring-up — validating register maps, interfaces, and boot / init sequences across the HW/SW boundary.
- Milestone sign-off: Contribute to verification exit criteria for design milestones, documenting coverage and open issues so the team can make informed tape-out / release decisions.
Required Qualifications
- Experience: 3–7 years of digital verification experience on FPGA or ASIC designs.
- Language: Proficiency in Verilog (SystemVerilog strongly preferred).
- Tools: Hands-on experience with logic simulators — Modelsim / Questasim and/or NC-Verilog.
- Methodology: Solid grounding in logic-simulation and verification fundamentals — testbench construction, constrained-random stimulus, functional / code coverage, and assertions.
- Education: BS/MS in Electrical Engineering, Computer Engineering, or a related field.
Strong Pluses
- Working knowledge of digital design and architecture (RTL design, pipelines, clock-domain crossing, bus / interconnect protocols).
- Experience collaborating with software / firmware teams on system bring-up and HW/SW co-validation.
- Structured verification methodology experience (UVM or equivalent).
- Familiarity with networking / switching datapaths or high-speed interfaces.
What Success Looks Like
- Zero Functional Escapes: The blocks you verify reach silicon and the field free of functional bugs, because your environment exercised the corner cases before anyone else could hit them.
- Coverage You Can Defend: Every milestone is cleared with documented functional and code coverage — no block signs off on "it seems to work."
- A Regression the Team Trusts: Fast, deterministic regressions catch breakage the same day it's introduced, so designers refactor with confidence.
- Bring-up Without Surprises: Because pre-silicon simulation matched real behavior, lab bring-up and HW/SW integration go smoothly — no late-stage firefighting.
