Mircea M. - Senior Software Engineer (Rails/React) | Threat Hunter

Cluj-Napoca, Romania

Experience

Nov 2024 - May 2025

7 months

Poland

Built and optimized Rails 7 microservices and React features for patient management to support a platform with >10M study participants.
Delivered compliant services on Docker and AWS ECS to speed deployments in a regulated environment.
Implemented Unleash feature flags, Sumo Logic observability, and Canva design tokens to speed safe releases and keep the UI consistent.
Developed a mobile-optimized UI with Web Components, Shadow DOM, and container queries to improve responsiveness across devices.
Stack: Ruby on Rails 7, React, TypeScript, Docker, AWS ECS, Unleash, Sumo Logic, Artifactory.

Dec 2023 - Sep 2024

10 months

Hong Kong

Parallelized asynchronous jobs to cut translation processing time from tens of minutes to under 1 minute.
Built and maintained product features in Rails, React, and Redux to expand the core platform.
Hardened APIs with security best practices to reduce exposure to common vulnerabilities.
Integrated OpenAI for rewrites and DeepL for machine translation to improve quality and reduce manual edits.
Evaluated a fine-tuned RoBERTa NER model to validate entity extraction quality; ran parser conformance suites and shipped a glossary workflow.
Stack: Ruby on Rails, React, Redux, Docker, AWS ECS, OpenAI API, DeepL.

Dec 2019 - Dec 2020

1 year 1 month

Romania

Built and operated a recommendation engine end-to-end on AWS; added Amazon API import, ratings, and a selection wizard to improve catalog coverage and UX.
Stack: Ruby on Rails, jQuery, Bootstrap, AWS.

Nov 2019 - Present

6 years 2 months

United States

Performed pentests and secure code reviews across Rails, Node.js, Python, and React and delivered remediation aligned with OWASP ASVS.
Test authentication, access control, rate limiting, input validation, session management and data security using ZAP, Burp Suite, and Postman.
Delivered security assessments and reports across authentication and SSO, access control and IDOR; data exposure and error handling; HTTP security headers and TLS; dependency risks; file and path handling and injection/unsafe reflection.

May 2013 - Sep 2018

5 years 5 months

Romania

Built an accounts receivable automation platform (Rails and JavaScript) to deliver invoice insights for SMEs.
Developed an ETL pipeline from historical invoicing data to generate reports used for lead generation, producing hundreds of prospects.
Audited and fixed billing defects across invoicing applications and an online course platform (10k-50k users), strengthened tests, and upgraded stacks (Ruby 1.8 to 2.*, Rails 3.2 to 5) while adding OAuth 2.0, impersonation, and API access control.
Stack: Ruby on Rails, Ember, Backbone, React, Stripe, OAuth 2.0.

Feb 2012 - May 2013

1 year 4 months

Romania

Implemented features for complex CAD geometries and large finite element models to meet client requirements.
Migrated Fortran components to C++ (STL, Qt, Boost) to modernize the graphics engine and enable plugin integration.
Stack: C/C++, STL, Qt, Boost, CAD/FEA.