Sr. Mechanical Development Engineer

Flex (Flextronics)

Quick summary

Work type: On-site
Location: Littleton, MA
Salary: $105,000–$144,400 / yr
Posted: 6 days ago
Closes: Sep 25, 2026
Nearby: 99+ roles within 25 mi

Market check

Salary context

Below market

How this pay compares to similar roles

Similar $167k

This role $125k

$94k most similar roles pay here $205k

This role pays less than 88% of similar roles. Most pay $138,912–$194,125 — the shaded band above. At the midpoint, this role pays about $125k versus about $167k for comparable roles.

Based on 240 similar postings.

Employer

About Flex (Flextronics)

Flex (formerly Flextronics) is a global technology, supply chain, and manufacturing solutions provider helping companies design, build, and deliver products across industries. Industry: Electronics Manufacturing Services

Flex (Flextronics) currently has 17 open roles on FindRole.

Listed pay typically runs $126,500–$173,900 across 9 roles with salary data.

Most-posted roles

View all roles at Flex (Flextronics)

At a glance

TL;DR · Sr. Mechanical Development Engineer

Role Posting Log in to save

As a Senior Mechanical Design Engineer at our Littleton, MA location, you will join the Product Development team to design and develop reliable liquid cooling systems for high-efficiency applications. Your daily tasks include creating detailed CAD models and 2D drawings, selecting materials for durability in liquid environments, and collaborating with thermal engineers on flow distribution and heat transfer efficiency. You’ll also conduct engineering analyses, build prototypes, and validate mechanical components through rigorous testing methods such as pressure tests and leak detection. Additionally, you will work closely with manufacturing teams to ensure designs are manufacturable and align fabrication processes with design requirements. The ideal candidate has a BS/MS in Mechanical Engineering and 7+ years of experience in developing complex mechanical systems, proficiency in CAD software like SolidWorks or Creo, and strong knowledge of fluid dynamics and heat transfer principles.

Skills

SolidWorks Creo NX CAD ASME Y14.5 GD&T Fluid Dynamics Heat Transfer Precision Machining Brazing Plating Elastomer Sealing Pressure Rated Components Materials Science Copper Aluminum Stainless Steel Polymers Elastomers Engineering Calculations Simulations Machining Sealing Pressure Testing Leak Testing Dimensional Inspection Materials Evaluation Mechanical Validation Testing

What you'll do

Own mechanical design for liquid cooling components including cold plates, manifolds, and quick-disconnects.
Perform engineering calculations and simulations related to thermal expansion, fatigue, vibration, and structural integrity.
Develop detailed validation plans for pressure tests, leak testing, burst testing, and environmental exposure.
Collaborate with manufacturing on fabrication methods and define critical-to-quality characteristics.
Lead root cause analysis for mechanical failures and implement corrective design changes.

What we're looking for

7+ years of experience developing complex mechanical components or assemblies for electro-mechanical systems.
Strong proficiency in CAD software (SolidWorks, Creo, NX) and GD&T standards.
Experience designing for precision machining, brazing, plating, elastomer sealing, and pressure-rated components.
Hands-on experience with pressure/leak testing, dimensional inspection, materials evaluation, and mechanical validation testing.
Familiarity with materials behavior in liquid coolant environments (copper, aluminum, stainless steel, polymers).
Strong technical expertise in mechanical design, structural evaluation, fluid dynamics, and heat transfer principles.
Excellent communication skills for leading technical decisions across cross-functional teams.

Similar roles

Mechanical Engineer

Anduril Industries

Costa Mesa, CA 24 days ago $129,000–$171,000

NX Solidworks Teamcenter ASME Y14.5 GD&T PCB design CNC machining Composites Sheet metal Injection molding 3D printing EMI constraints Passive/active thermal management Electrical engineering Software engineering Manufacturing engineering

Save

Lead Mechanical Engineer

Monroe, NC 65 days ago $164,612–$201,193

SolidWorks Inventor CREO FEA CFD Moldflow GD&T Statistical Analysis SCBA Pneumatic systems Hydraulic systems Precision machined parts Injection-molded parts High performance plastics Soft goods 3D solid modeling Design simulation

Save

Mechanical Engineer 4

Lam Research

Tualatin, OR 39 days ago

CREO Siemens NX ProE SolidWorks FEA GD&T FMEA 3D CAD tools thermal analysis stress analysis vibrations analysis fluid dynamics gas flow dynamics manufacturability analysis technical specifications risk analysis test specifications design review presentations

Save

Mechanical Engineer, R&D New Product Development

HP Inc.

Corvallis, OR 37 days ago $93,400–$182,400

CAD CoCreate/OneSpace Designer Design for Manufacturability (DFM) Microfluidics FAB processes High-volume manufacturing methods Phase-gate product development processes Mechanical engineering principles Manufacturing processes Joining technologies Injection molding Die casting Sheet metal Mechanical properties of materials Mechanical and fluid systems analysis Tolerances Stress/strain Thermal calculations Modeling tools Collaboration skills Communication skills

Save

Mechanical Design Engineer

TSC

Washington, DC 41 days ago $112,000–$190,000

SolidWorks 3D CAD/CAM AutoCAD Pro/E Inventor ANSYS MATLAB FMEA DFM Six Sigma Machining Processes Additive Manufacturing CNC Machining Injection Molding Hand Tools Power Tools Precision Measurement Equipment Tolerance Analysis Material Selection Fasteners Manufacturing Methods CI/CD

Save

Principle Thermal Mechanical Engineer

Flex (Flextronics)

Littleton, MA 20 days ago $153,500–$211,000

SolidWorks CAD GD&T DFM Fluid Dynamics Thermodynamics Heat Transfer Engineering Principles Simulation Software Documentation Tools Technical Communication Problem Solving Analytical Skills Research and Development Industry Standards Regulatory Requirements

Save