Walter W. | Elance
Last Sign-in: Feb 23, 2015

Walter W.

Unix/DB programmer/admin
  |   Caracas, Distrito Federal


Languages: C/C++, Java, UNIX scripting (sh, awk, Perl, tcl/tk)

O.S. Internals: UNIX (SysV, Solaris, Linux, True64, AIX, DG-UX).

WWW: iPlanet: Tuning/Admin/Internals, Apache: Tuning/Admin/Internals. Tomcat-Axis: Tuning/Admin/Internals. Plugin and Robots construction. HTTP/HTML/SOAP/XML parser construction from the RFCs. SSL integration and implementation. Web scripting.

RDBMSs: SYBASE: SQL Server, OpenClient DB-Library/C, Transact-SQL, ISQL. ORACLE: OCI, PL/SQL, User Exits at the engine level, Tuning & Admin. OpenAPI.

Networks and Communication Protocols: SNA/VTAM/NCP: LU2 and LU6.2 programming, APPC and CPI-C programming. TCP/IP: TCP/UDP programming using the socket interface. SLIP/PPP transport services. RPC and SNMP programming.

Security: SSL/TLS: Server and client programming, CA setup.
Hardening: Solaris, Linux, Oracle. Oracle data encryption. Support for PCI certification.

Voice/Data: Harris and Summa Four (CISCO) switch programming. IVR/ACD/CTI implementation.
Service Description
Several years of experience evolving into a proficient programmer and a think-ahead architect. Has been involved in cutting edge IT projects and successfully competing against big names like IBM, Computer Associates and Unisys. Some of those projects include:

Transaction Monitor design and construction
Compiler design and construction
Transparent TCP/IP sockets over SNA transport networks
Multitasked preemptive kernel for the x86 architecture
Multiplexing of several undisturbed processes over a single TTY
SCADA scheduler design and construction

The result of these challenging work was several times awarded with a job offering from the competition. It has been combined and in association with more mundane activities like:

Web programming, admin and internals
Database programming, admin and internals
Platform PCI certification
Hardening and security at the programming and admin level
Administration of Unix alike platforms
Switch programming at a PSTN
IVR/ACD/CTI programming
Some MS Windows admin and internals programming
Microcontroller programming
Coaching and mentoring

Being educated in the old school were performance was prime, and being trained by the tough competition against big brands, I had to make the transition by myself to technologies starting from OOP to IT approaches, which now are commonplace, like: RUP, Design Patterns and Agile Software Development.

Apart from the expertise mentioned above the specific hands-on experience and skills I offer as a freelancer includes, but are not limited, to:

Oracle admin and PL/SQL programming
PostgreSQL admin and internals
Apache Tuning/Admin/Internals
Tomcat-Axis Tuning/Admin/Internals
SSL/TLS server and client programming
TCP/IP sync and async programming
Multithreading and asynchronous programming
Unix scripting
Unix/Windows internals
Solaris Kernel internals

They are complemented with creativity and commitment with quality, timely delivery and convenient prices.
Ingedigit C.A.
Communications and Security Specialist
2000 - Present
Oracle migration/hardening and Solaris-Linux Hardening to be PCI compliant. Design/implementation of the scheduler for the "SCADA nacional" (PDVSA). Design and implementation of a middleware framework for UNIX and Windows XX. Extension of the middleware to handle 8583 message protocol to communicate with BASE24 systems on TANDEM machines. Agent and DB package to allow message based interaction between the middleware and a RDBMS. These components were used as the message pivot to communicate the banks to the Pre-Pay and Post-Pay systems at TELCEL. Accounting for VoIP ECI switches. RADIUS accounting for VoIP CISCO routers. Engine for automatic replication of Oracle DB to Tandem machines. Utility enabling the remote submission of batch jobs on Unix machines from WinXX or Unix machines.
Unisys de Venezuela C.A.
Architecture Specialist
1998 - 2000
Switch programming to connect an IVR/UVMS/ACD system to the CANTV PSTN. Construction of a 3270 engine allowing concurrent access to CANTV legacy systems in non-invasive fashion and providing a message based interface to client programs (UNIX, A Series, Windows XX, SNA LU2 and TCP/IP programming). Design and implementation of a compiler for the Ñ language (YACC, LEX). Design and implementation of middleware sub-system allowing to interconnect the PSTN branches with the central office (UNIX, Windows XX). Design and development of a library to precompile and process regular expressions. Consultant for voice/data communication systems and real time systems.
Computer Associates de Venezuela C.A
Systems Engineer
1997 - 1998
Technical support to data base products over midrange platforms. Support of products running above SNA networks. Object Oriented consultant. Integrator consultant.
Banco Unión C.A.
Systems Programmer
1995 - 1997
In charge of 32+ AIX-RS/6000 machines running above an SNA-TCP/IP network. To optimize the usage of this platform it was necessary the design and implementation of several systems as described. System to administer and interact with the native AIX spooler. Subsystem to allow and administer multiple full screen sessions over just one TTY (UNIX/IPC, pseudo-terminals). Subsystem to allow remote full screen sessions over a SNA network (LU6.2/APPC, UNIX/IPC, SNA/VTAM). Subsystem for remote command execution UNIX-to-UNIX, UNIX-to-HOST, HOST-to-UNIX and HOST-to-HOST over an SNA network (LU6.2/APPC, UNIX/IPC, NetMaster/SNA/VTAM). File transfer system between UNIX machines using the SNA backbone (LU6.2/APPC, UNIX/IPC, SNA/VTAM, compression algorithms). Development of shared libraries used as the foundation for other development workgroups (UNIX).
Payment Terms
None specified
Walter W. | Elance

Walter W.