Senior Full-Stack Microsoft Application Developer JASINT•3.3 Catonsville, MD Job Details Full-time $70,000•$80,000 a year 18 hours ago Benefits Health savings account Disability insurance Dental insurance Flexible spending account Paid time off Vision insurance 401(k) matching Referral program Qualifications 3 years Senior level

Full Job Description Job Title :

Senior Full-Stack Microsoft Application Developer Location(s) :

Baltimore, MD/Hybrid Hours:

Regular Full-Time Work Schedule:

Tuesday, Wednesday, and Thursday are office days•Baltimore, Maryland. Friday and Monday are Teleworking days.

Salary Range:

$70,000/yr•$80,000/yr

Clearance Requirements:

Must be able to complete a required fingerprint background investigation successfully.

What you will be doing:

JASINT is seeking a Senior Full-Stack Microsoft Application Developer (.NET 8 with MVC) to join us as a skilled .NET Integration Developer to design, develop, and deploy a robust .NET Console Application. The primary objective of this role is to automate data synchronization between the U.S. Environmental Protection Agency (EPA) RCRAInfo REST APIs and our internal Environmental Tracking System (ETS). The ideal candidate will have extensive experience handling secure RESTful web services, working with large

JSON/XML

datasets, implementing secure token-based authentication (OAuth2), and performing transactional database operations. This console application will be configured to run as a scheduled task, requiring high reliability, comprehensive logging, and efficient error handling.

API Integration:

Develop a .NET Core / .NET 8 console application utilizing HttpClient or RestSharp to securely authenticate and extract environmental data from the EPA RCRAInfo

REST API

endpoints (Handler, CME, e-Manifest, or WIETS modules).

Authentication Management:

Implement robust token lifecycle management for EPA API authorization (handling client credentials, token expiration, and secure storage of API keys).

Data Transformation & Mapping:

Parse, filter, and map complex hierarchical

JSON/XML

payloads received from the EPA services into flat or structured data objects compatible with the destination system.

ETS System Updates:

Upsert (Insert/Update) mapped data into the internal ETS system database (SQL Server, Oracle, or proprietary APIs) while maintaining data integrity and minimizing system locks.

Error Handling & Resiliency:

Implement advanced error handling, retry policies (using libraries like Polly for network transients), delta-loading (to only fetch data modified since the last run), and automated alert notifications for failed synchronizations.

Logging & Auditing:

Integrate a robust logging framework (e.g., Serilog, NLog) to capture step-by-step execution details, data volumes processed, and API response errors for compliance and debugging.

Position Requirements Minimum Requirements:

Experience:

Frameworks:

3-5+ years of professional development experience using .NET Core / .

NET 6 / .NET

8 and C#.

API Consumption:

Deep understanding of RESTful APIs, HTTP verbs, asynchronous programming (async/await), and handling authentication headers.

Data Serialization:

Expert-level knowledge of handling JSON data structure manipulation using System.

Text.

Json or Newtonsoft.

Json.

Databases:

Strong proficiency in SQL Server or Oracle, including writing efficient queries, handling bulk inserts/upserts, and using ORMs like Entity Framework Core or Dapper.

Tools:

Proficient with Git version control, CI/CD pipelines, and tools like Postman for API testing.

Education :

High School Diploma or GED Knowledge/Skills :

Analytical Problem Solving:

Ability to read through complex EPA Data Element Dictionaries (DED) and map them accurately to business requirements.

Autonomy:

Capable of picking up technical specifications, building a solution from the ground up, and testing edge cases without constant supervision.

Clean Code Principles:

Commitment to writing readable, maintainable, and well-structured C# code

Preferred Qualifications:

Prior experience dealing with environmental compliance systems or federal agency APIs (specifically EPA CDX or RCRAInfo Web Services). Experience implementing Polly for transient fault handling and Serilog for structured logging. Knowledge of deploying .NET console apps inside Docker containers or running them via Windows Task Scheduler / Azure WebJobs. Physical Demands This is largely a sedentary role; however, some filing is required. The ability to move files, open filing cabinets, and bend or stand as necessary would be required. Why JASINT ? At JASINT, we proudly boast a "together we can" attitude. That is only possible with a strong, talented team. Our goal is to answer the call to provide top mission and Warfighter support at all levels, and that's why we are seeking you! We understand and respect the dedication and sacrifice required to serve our nation's greatest efforts, and our commitment, in turn, is to Support You! JASINT cares about your work-life balance and offers competitive benefits to help you at every stage of your personal and professional life by providing the following: Retirement/401k with an employer match, employer-paid health, dental, vision for employees, flexible spending accounts (HSA/FSA), company partially funded HSA, STD/LTD, professional development, tuition and certification reimbursement, spot award recognition, PTO, Floating Holidays. •JASINT offers internal and external referral bonuses for all cleared exceptional talent we hire! Friends of yours are friends of JASINT! •JASINT provides equal employment opportunities to all employees and applicants without regard to race, color, ancestry, national origin, gender, sexual orientation, marital status, religion, age, disability, gender identity, genetic testing results, or military service. Equal employment opportunity applies to all terms and conditions of employment, including hiring, placement, promotion, termination, layoff, recall, transfer, leave of absence, compensation, and training. JASINT participates in E-Verify and will provide the federal government with I-9 information to confirm that all new hires are authorized to work in the U.S. To learn more about E-Verify, please visit dhs.gov/e-verify.