
Sean Austin Critica
Verified Expert in Engineering
Network Protocols Developer
Calamba, Philippines
Toptal member since March 26, 2018
Sean has over a decade of experience as a software and network engineer working with both small startups as well as large multinationals. He possesses a wide range of skills from networking, system administration, software development, and test automation. Sean joined Toptal to find work that values innovation and the entrepreneurial spirit—projects that involve more research and thinking than routine development work.
Portfolio
Experience
- C - 12 years
- Linux - 10 years
- Network Protocols - 10 years
- Robot Framework - 6 years
- Python - 6 years
- Jenkins - 6 years
- Ansible - 2 years
- OpenStack - 2 years
Availability
Preferred Environment
Vim Text Editor, Git, Linux
The most amazing...
...project I've worked on was a simulator that could generate a million mobile phone calls for performance verification of telco-grade equipment.
Work Experience
Product Architect
Nokia Networks
- Added new features and fixed bugs in the telco-network simulator used for performance testing of telco-grade equipment. Implemented using C, ASN.1, and Java.
- Implemented a test framework using Python that allows the instant reproduction of reported software bugs by replaying collected network traffic.
- Planned and set up an OpenStack cloud environment used by R&D for development and testing.
- Led the Nokia Garage team in implementing IoT, robotics, and electronics projects using Arduino and Raspberry Pi platforms.
- Was nominated for the AI/machine learning lead for a local tribe; responsibilities include establishing a competency development plan and evaluating machine learning initiatives.
Software Engineer
Nokia Networks
- Added new features, fixed bugs, improved the overall architecture of a telco-network simulator used for black box testing of telco-grade equipment. Implemented using C, ASN.1, and TTCN-3.
- Added new features and fixed bugs on an Eclipse plugin that adds support for a proprietary domain-specific language called TNDSL.
- Designed and implemented a static analyzer for user documentation (Java) to ensure conformance with the defined guidelines, including syntax and grammar checks.
- Created robot framework libraries and test cases using Python to reach the target coverage of legacy code bases.
- Was nominated as the team innovation champion which involved identifying and implementing process and tooling improvements to boost team efficiency.
Application Support Engineer
FixAsia Information Technologies, Inc.
- Ensured the uninterrupted operation of real-time market data feeds delivering data to automated trading algorithms.
- Created analysis tools using Perl for processing and analyzing large datasets to assist in troubleshooting system issues.
- Investigated and found the root cause of incorrect financial data reported by customers.
Senior Linux Development Engineer
Zvelo, Inc.
- Created an enterprise one-click VPN solution using SSL VPN with a Linux-based VPN backend, and custom front-ends for Windows, Mac, and Linux clients using C and C++.
- Developed an enterprise content filtering solution that allows rewriting of specific web page elements (like ads, images, malware, etc.) based on company-defined policies by implementing the ICAP protocol using C++ on a transparent proxy.
- Improved an enterprise anti-malware solution by supporting real-time scanning of large downloads without breaking the user experience (PHP).
- Contributed bug fixes and performance enhancements to the open-source Squid proxy server project.
Senior Technology Officer
Latitude Broadband, Inc.
- Wrote embedded software for network routers to handle access control and traffic shaping based on user profiles using C/C++, including kernel enhancements.
- Increased the WiFi access point capacity by modifying and optimizing firmware.
- Developed network management and CRM software for operating a wireless ISP network using LAMP.
- Conducted real-world performance and capacity testing of various wireless radio solutions.
- Planned, deployed, and operated a citywide wireless ISP network for Isocel Telecoms.
Education
Bachelor of Science Degree Cum Laude in Electrical and Electronics Engineering
University of the Philippines Diliman - Diliman, Quezon City, Philippines
Skills
Libraries/APIs
Flask-RESTful, TensorFlow, Keras
Tools
Vim Text Editor, Jenkins, Ansible, Git, VPN, PyCharm, Microsoft Power BI
Languages
C, Python, Perl, Java, TTCN, JavaScript, PHP, HTML, Bash Script, C++, Java 6, SQL, R
Frameworks
Robot Framework, Flask
Paradigms
Agile, ASN.1, Test Automation, Scrum, Six Sigma, Real-time Systems, Clean Code
Platforms
Linux, Kernel Programming, OpenStack, Docker, Eclipse
Industry Expertise
Network Security
Storage
MongoDB, PostgreSQL
Other
3G, Network Protocols, Wireless Communication, 2G, Embedded Software, Network Operations, Financial Market Data, Networking, ISO 9001, 4G
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