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Freelance Senior Software Developer Jobs (NOW HIRING)

OASYS, INC.

Senior Software Developer

Huntsville, AL · On-site

$50.75 - $67/hr

Senior Software Developer OASYS, INC ., a Leading-Edge Government contractor in Huntsville Alabama, is seeking a Senior Software Developer to support our ARMY/MDA customer onsite at Redstone Arsenal ...

FMT Consultants

Senior Software Developer

Carlsbad, CA

$56.50 - $74.75/hr

The senior software developer resource will work with team members and clients in the development and delivery of customizations generally related to various Microsoft applications and technologies ...

FMT Consultants

Senior Software Developer

Carlsbad, CA · On-site

$56.50 - $74.75/hr

The senior software developer resource will work with team members and clients in the development and delivery of customizations generally related to various Microsoft applications and technologies ...

OASYS

Senior Software Developer

Huntsville, AL

$53.75 - $71/hr

Senior Software Developer OASYS, INC ., a Leading-Edge Government contractor in Huntsville Alabama, is seeking a Senior Software Developer to support our ARMY/MDA customer onsite at Redstone Arsenal ...

OASYS, INC.

Senior Software Developer

Huntsville, AL · On-site

$50.75 - $67/hr

Senior Software Developer OASYS, INC ., a Leading-Edge Government contractor in Huntsville Alabama, is seeking a Senior Software Developer to support our ARMY/MDA customer onsite at Redstone Arsenal ...

State of Oregon

Senior Software Developer

Salem, OR · On-site

$6.8K - $10K/mo

Senior Software Developer Information Systems Specialist 7 - Senior Software Developer Oregon Department of Transportation Support Services Division - Information Systems Branch Enterprise ...

Tandym Tech

Senior Software Developer

Woodcliff Lake, NJ · On-site

$57.75 - $76.25/hr

A professional services firm is seeking a new Senior Software Developer to work on complex and evolving challenges across the full engineering landscape. ***This is a Remote opportunity.

Verdant

Senior Software Developer

Brackettville, TX

$50 - $66/hr

We are looking for a full stack Senior Software Developer to join this team. Verdant is a fast-paced business that provides numerous opportunity to grow and evolve. Our team members need to be ...

Hirekeyz Inc

Senior Software Developer

Fairfax, VA · On-site

$55.75 - $73.50/hr

Role: Senior Software Developer Location: Onsite- Fairfax, VA 3 Days and in Washington, DC 2 Days per Week. Duration: Long Term Contract Position Require a Secret Clearance The Senior Software ...

Saalex

Senior Software Developer

Lexington Park, MD · On-site

$145K - $190K/yr

Salary: $145k-$190k (depending on experience) We are seeking an experienced Senior Software Developer to design, develop, and enhance software solutions that support mission-critical systems. This ...

Apex Informatics

Senior Software Developer

$55.75 - $73.75/hr

Senior Software Developer (Python +JavaScript) LinkedIn recommendation is a must. * 15800 Northup Way Bellevue Washington 98008 United States * 100% Remote * 12 months assignment Must have : • 5+ ...

Saalex

Senior Software Developer

Lexington Park, MD

$145K - $190K/yr

Salary: $145k-$190k (depending on experience) We are seeking an experienced Senior Software Developer to design, develop, and enhance software solutions that support mission-critical systems. This ...

Verdant

Senior Software Developer

Brackettville, TX · On-site +1

$50 - $66/hr

We are looking for a full stack Senior Software Developer to join this team. Verdant is a fast-paced business that provides numerous opportunity to grow and evolve. Our team members need to be ...

Ra

Senior Software Developer

New York, NY

$59.50 - $78.75/hr

Senior Software Engineer Job Level : Senior Level Job Location: New York, NY Industry: Start Up THIS IS WHAT YOU WILL DO... You will collabrate with design and product members to define customer ...

Saalex

Senior Software Developer

Lexington Park, MD · On-site

$145K - $190K/yr

Salary: $145k-$190k (depending on experience) We are seeking an experienced Senior Software Developer to design, develop, and enhance software solutions that support mission-critical systems. This ...

Prescient Edge

Senior Software Developer

Doral, FL · On-site

$52.25 - $68.75/hr

Job Title Senior Software Developer Location Doral, FL 33122 US (Primary) Category Intelligence Job Type Full-Time Career Level Staff Education Bachelor's Degree Travel Security Clearance Required TS ...

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Freelance Senior Software Developer information

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How much do freelance senior software developer jobs pay per hour?

As of Jul 18, 2026, the average hourly pay for freelance senior software developer in the United States is $61.73, according to ZipRecruiter salary data. Most workers in this role earn between $52.40 and $69.23 per hour, depending on experience, location, and employer.

What are the key skills and qualifications needed to thrive as a Freelance Senior Software Developer, and why are they important?

To thrive as a Freelance Senior Software Developer, you need advanced programming expertise, a robust portfolio, and significant experience with full software development lifecycles. Strong command of frameworks, version control (like Git), cloud platforms, and potentially certifications such as AWS Certified Developer or Microsoft Certified: Azure Developer are highly valuable. Exceptional communication, time management, and problem-solving abilities help you effectively collaborate with clients and manage multiple projects independently. These skills ensure you deliver high-quality, timely solutions while building a strong professional reputation in a competitive freelance market.

How do Freelance Senior Software Developers typically manage client expectations and project timelines?

Freelance Senior Software Developers often juggle multiple clients and projects, which requires clear communication and proactive expectation management. They usually begin by setting detailed project scopes, timelines, and deliverables with clients, then provide regular updates and adjust schedules as needed to accommodate changes or unforeseen challenges. Strong time management skills and transparent reporting help ensure that projects stay on track and that clients remain informed and satisfied throughout the development process.

What is the difference between Freelance Senior Software Developer vs Freelance Software Engineer?

AspectFreelance Senior Software DeveloperFreelance Software Engineer
CredentialsTypically requires extensive experience, advanced coding skills, and sometimes certifications like Microsoft or AWSRequires solid coding skills and experience, often with relevant certifications but generally less senior-level expertise
Work EnvironmentWorks independently or with clients directly, often on complex projects requiring leadershipWorks independently or with teams, focusing on software development tasks across various projects
Industry UsageCommonly used in consulting, freelance platforms, and project-based work requiring senior expertiseWidely used in freelance and contract roles across tech industries for development tasks

The main difference lies in experience level and project complexity. Freelance Senior Software Developers typically handle more complex projects and provide technical leadership, while Freelance Software Engineers focus on coding and development tasks across a range of project types.

What does a Freelance Senior Software Developer do?

A Freelance Senior Software Developer designs, develops, and maintains complex software systems for clients or companies on a contract basis. They often work independently, managing multiple projects, collaborating with stakeholders, and ensuring the delivery of high-quality code. Their role may include mentoring junior developers, making architectural decisions, and troubleshooting technical issues. Freelancers have the flexibility to choose their clients and projects, and they are responsible for managing their own workload, deadlines, and business operations.
What cities are hiring for Freelance Senior Software Developer jobs? Cities with the most Freelance Senior Software Developer job openings:
What are the most commonly searched types of Senior Software Developer jobs? The most popular types of Senior Software Developer jobs are:
What states have the most Freelance Senior Software Developer jobs? States with the most job openings for Freelance Senior Software Developer jobs include:
Freelance Senior Software Developer jobs near you
Senior Software Developer

Senior Software Developer

OASYS, INC.

Huntsville, AL • On-site

$50.75 - $67/hr

Full-time

Dental, Vision, Retirement, PTO

Posted 21 days ago

Job description

Senior Software Developer

OASYS, INC., a Leading-Edge Government contractor in Huntsville Alabama, is seeking a Senior Software Developer to support our ARMY/MDA customer onsite at Redstone Arsenal, Huntsville, AL.

Job Responsibilities include: You will help drive the technical evolution of mission-critical warfighter training and planning tools. This Java based tool provides warfighters and sensor managers with the ability to rapidly plan, optimize, and deploy layered sensor search plans in operational timelines. Your knowledge and skills will directly enhance the survivability and battlespace awareness of fielded assets, integrating high-fidelity intelligence data, complex physics-based models, and tactical hardware health into a streamlined operational tool.

  • Support the software design for the core man-in-the-loop graphical user interface, the Rapid Response Tool (RRT), and the Socrates parsing utility.
  • Design and maintain seamless interoperability with external intelligence and modeling frameworks, specifically the Threat Generation External (TGx) and the Threat Modeling Center (TMC) Threat Modeling & Simulation Suite (TMSS).
  • Lead the implementation of heuristic algorithms for search plan optimization, deterministic statistical roll-ups for Probability of Acquisition (Pacq), and 4/3 Effective Earth Radius models for terrain masking (using DTED).
  • Ensure robust data ingestion and export pipelines for tactical log data from radars and tactical binary search plan files (SPT, OSP, Custom XML).
  • Support the software team in adopting DoD DevSecOps best practices, ensuring all code meets rigorous cybersecurity standards for deployment in operational military environments.
  • Contribute to a team of software engineers and radar systems analysts in translating complex physics and engineering models into scalable, performant software code.

Minimum Requirements:

  • Bachelor's or Master's Degree in Computer Science, Software Engineering, Systems Engineering, or a highly related technical field.
  • 10+ years of full-lifecycle software engineering experience
  • Strong programming expertise in modern languages utilized for defense modeling and UI (C++, Java, Python).
  • Experience with XML data structures and parsing utilities.
  • Familiarity with geospatial data processing and coordinate geometry (e.g., Vincenty Direct formulas, DTED/TDF integration).
  • Experience developing software within the DoD Modeling and Simulation (M&S) enterprise.

Preferred Requirements:

  • Direct experience with phased-array radar systems
  • Familiarity with threat models
  • Knowledge of radar detection theory, Signal-to-Noise Ratio (SNR) tracking logic, and Scattering Center Radar Cross Section (RCS) models.
  • Previous experience supporting rapid prototyping and Warfighter Improvement Process (WIP) requirements.

Required Education: Candidates should possess a bachelor's degree, preferably in Engineering, Cyber, Computer Information Systems, Computer Science, Math, Physics, or other STEM discipline, however, years of experience may be substituted for a degree.

Eligibility: Candidates must have the ability to obtain and maintain a DoD Secret Clearance. An Active Secret Clearance is highly desired.

About OASYS, INC.: Located in Huntsville, Alabama, OASYS, INC. is a technology services and products company dedicated to delivering the right solutions to our government and commercial clients. Our innovative solutions combined with today's technology and our subject matter expertise help to provide full lifecycle support for our client's needs.

Benefits: OASYS, INC. offers a robust benefit plan to include: BC/BS of Alabama Heath & Dental, VSP Vision, Employee Stock Ownership Plan (ESOP), 401-K with Matching, Flexible Spending Account, Tuition Reimbursement, Holidays, Vacation, Short-term/Long-term Disability.

www.oasys-incorporated.com

EOE AA M/F/Vet/Disability Equal Employment Opportunity is the Law: http://www1.eeoc.gov/employers/upload/eeoc_self_print_poster.pdf


Job Posted by ApplicantPro