Resume of Vyacheslav L. Zavadsky

I was responsible for  web site of  BraySystems, Inc. The assignment was to demonstrate the company's use of web  technologies and to integrate to a typical  site complex server-side effects. One effect was invented and implemented especially for this web site: 

• Adaptive news panel. A news item is marked as new till the user sees the page related to the item

 
• In February 1999 I participated in several discussions regarding  database and software architecture. I pointed at this conference that the  architecture they had in mind  could  lead to tough  scalability issues. However, my viewpoint was virtually not taken into account
• In September 1999 I was invited to address those very same scalability issues I predicted earlier. I had to meet a  three-day deadline . I found that  a flaw in  database design causes  a single nontrivial query to  take about 5 minutes and  to often lead to core dump of SQL server (interbase) or CGI scripts. The emergency decision  was to move the server from NT to Linux (that is much more resistant to memory leaks) and  to recode the main search script (I did the recoding with the help of the original author). The database's  perfomance impoved considerably  (several seconds per query).
• In December 1999 the master database grew to such a scale that most SQL engines (even Oracle's)  could not deliver  an acceptable perfomance (a complex query utilizes about 5 minutes on Interbase and 1-2 minutes on Oracle). I was called in to resolve the situation without  major software changes. I came up with an   architecture that wased based  both on their SQL database and some  free web site search engines.  The solution was implemented by the company's staff under my supervision. Queries now take less than a second. 

I also participated in several free software projects as beta tester/bugs hunter. I found small bugs and workarounds for them in PHP, Linux Networking Code, Russian Apache. 

 
• CNC control server under Linux. MZOR produces CNC programs using SGI workstations, but uses this programs on CNC machines equipped with  legacy PDP11 based controllers. The programs became larger and larger and occupied several Mbs, but the controllers have only 32 Kb RAM. So, we needed either to replace the CNC controllers and software involved (that costs more that $100,000 per machine) or come up with something new. I, in cooperation with the production engineers, used  the EPP ports of the  personal computers wired to the perfotape ports of the CNC controllers to emulate perfotape reading device by PC. This was done by a special kernel level driver. This way, our production engineers can control the CNC machines directly from their offices using the Samba printing services of the CNC control server.
• Internet connectivity (firewall, X25, adaptation of free software packages (Exim, Cyrus Imap suite) for our requirements -LDAP integration and Russian language support, domain registration, proxy, WWW etc.) This assignment involves writing Apache and Squid modules to synchronize their data to our LDAP catalog, some changes in linux network code. 
• Corporate news management systems (Perl/Apache/MySQL); database for enterprise wide accounting of valuable metals (Access, ReportSmith); suite of macros for automatic packaging design (Excel/T-Flex CAD, project leader); development of a mathematical model for online digital measurements in balancing machines (wavelets, optimal linear operators - Mathematica, C++), engineering calculations of precise milling  in balancing machines (multivariate approximations - C++, Mathematica)
• Development of PDM software (Delphi/Interbase, project leader); quality assurance software (first version QA, second - Access); cross assembler suite for PDP 11 (first version Turbo Pascal, second - Modula/2+Yack); copy protection software development; copy  protection software  cracking.

Since 1994 -postgraduate student/research assistantship. Since 1997 - temporary research associate.