Top Principal Engineer Jobs in Los Angeles, CA

Design and verify digital systems for space applications: develop RTL (VHDL/Verilog), ASIC/FPGA architecture, run simulation/emulation, synthesis, timing analysis, equivalence checks, and create verification plans and testbenches (SystemVerilog/UVM). Perform lab integration, trace requirements, and review/audit test procedures. Position may require government security clearance and is contingent on program funding.

Develop architectures and requirements for emerging EO/IR sensor systems. Perform EO/IR sensor performance analysis, modeling, and simulation to evaluate sensor designs and enable program decisions. Support advanced modeling efforts and collaborate across teams; position contingent on program award and funding.

Lead optical design, integration, and test of high‑power solid‑state laser systems (fiber and slab), develop productized laser solutions, perform system tests and diagnostics, present technical briefings, and support program development within defense space systems.

Lead mechanical engineering design, analysis, and qualification for valves, actuators, and flow control devices used in advanced and existing nuclear power plants. Perform structural/stress, thermal, and seismic/dynamic analyses, develop technical solutions, advise on materials, create industry-standard reports, and collaborate across teams and with customers to improve and qualify products.

Lead design, development, test, and integration of complex digital hardware for spacecraft flight programs. Create circuit and board designs, perform unit architecture, manufacturing, assembly, verification, and design validation. Support test systems, design reviews, and cross-functional engineering efforts.

Lead software quality efforts including developing and maintaining quality evaluation plans, V&V testing, audits, metrics collection, and corrective actions. Collaborate with program, engineering, and process groups to ensure quality standards and QMS compliance across software and system products.

Lead technical authority for spacecraft EMI/EMC: set system- and unit-level EMC requirements, define grounding/bonding/shielding/filtering architectures, drive MIL-STD-461 and GSFC-7000 qualification, perform pre-compliance analysis, diagnose EMI issues, develop test capability and procedures, and establish EMI/EMC standards and mentorship across programs through production and launch.

Develop and integrate embedded software for advanced aerospace and tactical systems. Responsibilities include full SDLC participation, C/C++ development, software debugging and testing, peer reviews, requirements implementation, technology evaluation, and collaboration with systems, hardware, and integration teams in an Agile environment. The role is onsite in El Segundo, California, requires a Secret clearance at start, and involves approximately 10% travel.

The Principal Software Engineer will design and implement systems for the advertiser experiences at Snap, lead technical vision, mentor engineers, and innovate on creator marketplace products.

Design and build next-generation ads formats, backend infrastructure, and scalable distributed systems. Lead technical direction, collaborate across teams to define product requirements, experiment, analyze and optimize ad performance, and ensure availability, scalability, operational excellence, and cost management. Mentor engineers and apply AI tools and high-velocity workflows to deliver production-ready systems.

The role involves architecting spacecraft-wide harness solutions, establishing standards and automation tools, overseeing manufacturing strategies, and mentoring engineers across teams.

Lead architecture, design, and delivery of PET product features; write production full‑stack code; champion testing, observability, CI/CD and operational readiness; mentor engineers and collaborate with product to shape technical roadmap.

Design and develop massively parallel distributed database kernels for real-time analytics at terabyte and petabyte scale. Responsibilities include low-level C++ development, MPP query execution, SIMD and hardware optimization, distributed communication using MPI and RDMA technologies, database internals, vector indexing, in-database machine learning, performance tuning, architecture reviews, mentoring, and resolving scalability issues.

The Principal Software Engineer will design automated ad serving systems, lead technical direction, collaborate with teams, and mentor engineers.

Design and develop Mechanical Ground Support Equipment (MGSE) for spacecraft integration and test. Responsibilities include 3D CAD modeling, GD&T drafting, first-order structural analysis, fabrication/vendor support, requirements definition, design reviews (PDR/CDR), producing drawings and work instructions, resolving non-conformances, and supporting integration and test operations.

Lead architecture, development, and validation of end-to-end aircraft fuel systems. Drive cross-functional integration, system-level modeling (CFD), verification, supplier qualification, ground and flight test support, anomaly root-cause analysis, and mentor engineering teams while contributing to long-term fuel-system technology roadmaps.

Lead the architecture and operation of Yahoo’s enterprise developer experience platform, including CI/CD, artifact management, GitOps deployments, and developer tooling. Design production agentic AI automation with evaluation frameworks, correctness checks, and security guardrails. Establish standardized workflows, templates, and CI practices; improve developer productivity through AI-assisted engineering and self-service portals. Partner with security and compliance teams, provide technical leadership, guide architecture reviews, mentor engineers, and measure platform adoption and reliability.

The Principal Engineer will shape the technical strategy for messaging infrastructure, influence architectural decisions across teams, and solve complex technical problems. Responsibilities include mentoring engineers, driving coherence across teams, and leading initiatives to ensure Weave's competitiveness in messaging solutions.

Design, model, test, and analyze component- and system-level survivability across RF, IR, VIS, and acoustic spectrums. Plan and execute RCS/RF tests, develop materials/processes, integrate mission systems, coordinate with designers and suppliers, and deliver test analyses and recommendations to reduce system detectability.

As a Senior Principal Engineer, you'll define and drive the technical strategy for customer experience platforms, lead architectural decisions, and mentor engineering teams to enhance customer and agent experiences.

Lead design, build, deployment, and operation of highly resilient, high-throughput configuration and publishing systems. Define long-term architecture and strategy, mentor senior engineers, diagnose and fix performance bottlenecks, and leverage AI tools to improve engineering productivity and platform capabilities.

Architect, build, and operate multi-cloud (AWS/Azure) network infrastructure across classified environments (IL-4/5/6+) supporting DoD/IC programs. Lead cloud network design, IAM, boundary protections, RMF/ATO support, STIG/SCA remediation, and compliance with NIST 800-53 and related NSS frameworks.

Design and deliver core platform capabilities for FloQast Transform, building scalable, resilient distributed systems, AI agent infrastructure, and a visual workflow builder. Lead high-level architecture and engineering best practices, translate product needs into technical roadmaps with Product and Design, and mentor senior engineers to raise team performance and delivery.

Lead systems architect for Command and Control Enclave (C2E) delivering tailored architectural solutions, trade studies, and integration approaches. Define hardware, software, networking, and support architectures, validate requirements, analyze performance and interfaces, and produce technical documentation and design reviews to meet contract deliverables while applying rigorous engineering processes.

Develop, implement, and verify guidance, navigation, and control (GNC) algorithms and simulations for manned and unmanned fixed-wing air vehicles. Create control laws, build linear and non-linear dynamic models, run hardware-in-the-loop and flight-test analysis, and support design reviews and autonomy logic for inner/outer loop control and autopilot functions.