Materials Testing Engineer Jobs in California (NOW HIRING)

Reliability Validation & Testing Engineer
Role Overview
We are seeking a hands-on Reliability Validation & Testing Engineer to lead product reliability validation throughout the NPI lifecycle. This role is primarily focused on designing, executing, and analyzing reliability validation testing across electrical, mechanical, thermal, and environmental domains.
The engineer will own the full validation strategy - from test planning through execution, data analysis, failure investigation, and design feedback - ensuring products meet reliability targets before production ramp and customer release. The ideal candidate combines strong engineering fundamentals, lab testing expertise, and structured problem-solving capability grounded in reliability engineering principles.
Essential Duties and Responsibilities
To perform this job successfully, the individual must be able to perform each essential duty satisfactorily.
Reliability Strategy & Test Planning

• Develop product reliability validation strategies aligned with reliability targets (MTBF, mission profile, warranty life, field exposure risk).
• Create and own DVP&R (Design Verification Plan & Report) focused on reliability validation and accelerated life testing.
• Translate customer requirements, use cases, and environmental exposure into structured validation plans.
• Define accelerated test profiles (HALT, HASS, vibration, thermal cycling, shock, humidity, power cycling, etc.).

Hands-On Validation Testing

• Execute electrical, mechanical, environmental, and thermal reliability tests.
• Design and build test fixtures when required.
• Usage of Instrument products with sensors (thermocouples, strain gauges, data loggers, etc.).
• Develop test automation where applicable.
• Monitor, log, and validate test data integrity.

Failure Analysis & Risk Assessment

• Lead failure investigations from lab or field returns.
• Conduct structured root cause analysis (8D, fishbone, fault tree, Weibull analysis).
• Perform field exposure risk assessments and containment planning.
• Drive corrective actions into design and process teams.
• Apply Physics-of-Failure principles to understand degradation mechanisms.

Data Analysis & Reporting

• Perform statistical analysis of test results (Weibull, life data analysis, confidence intervals).
• Evaluate reliability growth trends.
• Present technical findings clearly to cross-functional stakeholders and leadership.
• Maintain thorough validation documentation for regulatory and customer audits.

Cross-Functional Collaboration

• Work closely with design engineering to influence product robustness early in development.
• Partner with manufacturing engineering to ensure validation learnings are incorporated into production controls.
• Support qualification builds and pilot runs.
• Contribute to FMEA (DFMEA, PFMEA) updates based on validation findings.

Minimum Qualifications
The requirements listed below are representative of the knowledge, skill, and/or ability required. A reasonable accommodation may be provided to enable individuals with disabilities to perform the essential functions.
Education & Experience

• Bachelor's or Advanced degree in Mechanical, Electrical, or Materials Engineering.
• 3-6 years of experience in reliability validation, test engineering, or product validation roles. Strong lab-based hands-on testing experience required. New graduates with extensive thesis/lab research in reliability testing may be considered.

Required Knowledge, Skills & Abilities

• Strong understanding of reliability engineering fundamentals:
  • Acceleration models (Arrhenius, Coffin-Manson, inverse power law)
  • Reliability growth methods
• Experience creating and executing DVP&R plans.
• Hands-on experience with:
  • Environmental chambers
  • Vibration and shock testing
  • Thermal cycling
  • Electrical load testing
  • Data acquisition systems
• Ability to interpret engineering drawings and GD&T.
• Statistical analysis capability (Excel, JMP, Minitab, Python preferred).
• Structured problem-solving skills (8D, DMAIC, fault tree).
• Strong documentation discipline

Preferred Qualifications

• Experience with HALT / HASS methodologies.
• Experience performing life data modeling and Weibull analysis.
• Familiarity with APQP and DFMEA integration.
• Experience in high-volume manufacturing environments.
• Experience in regulated industries (automotive, battery, aerospace, etc.).
• Experience developing automated test setups or scripting test sequences.
• Knowledge of reliability standards (IEC, UL, ISO, MIL-STD, etc.).

Personal Attributes

• Hands-on engineer who enjoys working in the lab.
• Comfortable operating in ambiguous startup environments.
• Detail-oriented with strong ownership mentality.
• Strong technical communicator (verbal and written).
• Self-starter who takes initiative and drives problems to closure.

Physical Demands and Work Environment
The physical demands described here are representative of those that must be met by an employee to successfully perform the essential functions of this position. Reasonable accommodations may be made to enable individuals with disabilities to perform the functions.
Working Conditions/Hours:
Salaried Exempt
Physical Demands - Office and Manufacturing Environment
While performing the duties of this position, the employee is regularly required to talk or hear. The employee frequently is required to use hands or finger, handle, or feel objects, tools or controls. The employee is required to stand; walk; sit; reach with hands and arms and pull/push; climb or balance; and stoop, kneel, crouch, or crawl. The employee must lift and/or move up to 50 pounds without assistance. Specific vision abilities required by this position include close vision, distance vision, color vision, peripheral vision, and the ability to adjust focus.
Work Environment -
Includes both a typical office environment, with minimal exposure to excessive noise or adverse environmental issues, and a shop environment, with exposure to high noise levels from operating machines, physical hazards from moving equipment and machine parts, nuisance dust, and skin exposure to chemicals used to run/maintain machines
PPE-
May be required to wear Personal Protective Equipment, including but not limited to safety glasses, safety shoes, bump-caps, gloves, hair nets, masks, & clean-room frocks while adhering to the prescribed safety procedures.
The base pay is just one part of CelLink's total compensation package and is determined within a range. The pay range is designed to support your career progression as you learn, grow, and develop within your role. Your base pay range will depend on your skills, qualifications, experience, and location.
At CelLink, we believe that each employee should have the opportunity to become a CelLink shareholder through participation in CelLink's discretionary employee stock option plan. You'll also receive comprehensive medical and dental coverage and other great benefits.
Note: CelLink benefits, compensation, and employee stock programs are subject to eligibility requirements.
San Carlos, CA Base Pay
$90,000-$140,000 USD
We believe diversity and inclusion among our teammates are essential to our success. We celebrate diversity and are committed to creating an inclusive environment for all employees while building teams that represent a variety of backgrounds, perspectives, and skills. We are an equal opportunity employer. All employment is decided based on qualifications, merit, and business needs. CelLink participates in the E-Verify program in specific locations as required by law.
CelLink was founded in 2012 and entered volume production in 2018. CelLink provides electrical systems to the world's leading automotive OEMs & EV manufacturers, data center developers, and stationary power companies. The company has raised approximately $315M in funding through private investment and multiple grants from the US Department of Energy. CelLink's investors include 3M, Atreides, BMW, BorgWarner, Bosch, D1 Capital, Fidelity, Fontinalis Partners, Ford, Franklin Templeton, Lear, Park West, SK Telecom, Standard Investments, T. Rowe Price, Tinicum, and Whale Rock.