QA Analyst/ Developer

Sergio Samayoa

Bulevar Hospital Militar **-** zona 16 #75 Guatemala,

Central America, 01016

Cell: (502-****-**** -

******.*.*******@*****.***

Highly skilled systems architect and developer with more than 25 years of

experience designing,

developing and deploying applications, from old single platform

“green-screen“ to multi-tier /

distributed systems. Business experience in manufacturing, accounting,

distributing, payroll,

finance and TELCO.

Qualifications

Strong knowledge of Java SE and JEE stacks, from early versions 1.x

up to latest version

SE 7 and JEE 6.

Deep understanding of old technologies such Cobol, ISAM, flat

files, pipes, “green screen”,

etc. This knowledge allowed me to design, code and implement

integrations between new

applications with legacy ones.

Solid leading and mentoring skills helping and encouraging

individuals to maximize their

productivity applying best practices, frameworks, libraries and

technology in general.

I'm always learning new technologies and tools to easy and reduce

the time spend in

application development and deployment. Technology by it self worth

nothing if does not

resolved real world problems.

Technical Expertise

Languages Java, SQL, Oracle's PL/SQL, Object

Pascal (Delphi & FPC),

Cobol, XML, JavaScript

Java frameworks

EJB, JPA, JMS, CDI, JAX-WS, JAX-RS,

JSF, RichFaces, JSP,

JSR-233 (Java scripting)

Java libraries

Apache Commons, Apache POI,

JasperReports, BIRT

Java IDEs

Eclipse, Netbeans, Oracle's OEPE,

JBoss Tools 3.x

Used java containers

Glassfish 3.x, Apache Tomcat 6 & 7,

JBoss 4.x & 5.x, Weblogic

10.x, Websphere 6.x

Databases

Oracle, Firebird, DB2/UDB

JavaScript frameworks

Sencha's ExtJS 4.x

Other skills

Continuous integration (Hudson)

Version control (CVS and SVN)

Platforms

Windows, Unices (Linux, Tru64, AIX,

HPUX), AS/400

Sergio Samayoa

Bulevar Hospital Militar 15-01 zona 16 #75 Guatemala,

Central America, 01016

Cell: (502-****-**** - ******.*.*******@*****.***

Professional Experience

ICON Guatemala, Guatemala, Central America

Systems Architect / Senior JEE Developer - 2001 to present

Latest projects:

Promotion sales system via SMS / for regional (Central America) TELCO company / 2011

Extensible sales system via SMS for prepaid and postpaid customers.

Customer sends a keyword to designated number (ex: 777) via SMS to buy promotions such long

distance calls plans, temporal Internet access, reduced fare (friends and family), consumption plan

change, inquiry balance, etc. The system checks if the subscriber qualifies for customer's desired

promotion according to configured business rules (plan type, consumption plan, age, current

balance, recharge history, etc.), charges the subscription fee (if any) then provisions the

appropriated systems and/or platform (billing, CRM, HLR, RIM, prepaid platform, etc.).

When subscription ends, system does the deprovisioning where needed (down an APN in HLR for

example). System is capable of handling up to 20 requests per second on moderate hardware.

Currently deployed in 1 country, expected to be deployed in another 4 countries in early 2012.

Role: Architect / lead developer.

Technologies: EJB 3.0, JMS 1.1, JPA 2.0, JSF 1.2 + RichFaces 3.x, Oracle 10g, Weblogic 11g.

Customer portal / for South American TELCO company / 2010

Our customer has portal which was over its useful life. Instead of improving it, we were

contracted to develop a new portal using JEE technologies. The daunting part of the project was

the integration to heterogeneous systems written in different languages and technologies: SOAP< Web Services (we have a lot of trouble with several of them), direct MS SQL Server access,

SOAP Java Web Services hosted on old Weblogic 8 server(s), Tuxedo services, SAP Web

services, etc. Worst of all, documentation were scarce and inaccurate. To get subscriber's data we

have to access from 5 to 10 different systems just to show customer's general information so we

have to use threading inside JEE container. We had to parse text data to get some billing

information. Even with all the problems, the product was delivered in scheduled time and was

greatly accepted by final users. Application has about a 1 million users.

Role: Architect / team leader

Technologies: EJB 3.0, JSF 1.2 + RichFaces 3.x, WTC, Web Services, Birt, Oracle 10g, MS SQL

Server 2000, Weblogic 11g

Sergio Samayoa

Bulevar Hospital Militar 15-01 zona 16 #75 Guatemala, Central America, 01016

Cell: (502-****-**** - ******.*.*******@*****.***

Free lance projects, Guatemala, Central America.

Even if most of the time I have a permanent position at some company, I develop and deploy

applications in my spare time.

Latest projects:

Java to Cobol Bridge (J2C) / Herring Bank, Amarillo, Texas (remote) / 2010 - 2011

Herring Bank has a RM/Cobol system which manages the balance on debit cards.

This Cobol system was accessed by other systems using an old in-house crafted

gateway via TCP/IP sockets. The problem with this gateway was performance: very sluggish.

Requirement was 10+ transactions per second against mockup Cobol System.

After 3 iterations, the new gateway I wrote exceeded this requirement: in test environment reached

285+ transactions per second against mockup Cobol program.

I was told that in production using real Cobol System with real clients, the overall performance was

the target 10+ transactions per second per process. The most time consuming part of the system is

socket overhead (each client connects/disconnects to/from server for each transaction) which is

little more than 60% followed by actual Cobol System transaction processing, about 30%; less than

10% of the time is spend in the gateway.

Technologies: Java 6, Threading, Sockets, AIX named pipes, RM/Cobol.

IPAuthorizer / OSI de Guatemala / 2010

Local bank's customers were victims of phishing in early 2010. Bank's officials were very worried

about this and contacted “OSI de Guatemala” to help them on strengthening their eBanking

software. I designed, wrote and deployed a simple yet powerful application called IPAuthorizer

which, using a rule based engine, allows or denies request based on user's IP address, data taken

from web agent and access history for each particular user.

Technologies: JSF 1.2 + RichFaces 3.x, JAX-WS, JSR-223 (Java scripting), Oracle 10g, JBoss 4.x

Previous jobs.

Mezcladora S.A. (ready mix), Guatemala, Central America

Development Manager, 1993 - 2001. Pascal, Delphi, Novell, Btrieve, Oracle.

Zeus Sistemas (consulting), Guatemala, Central America

Co-owner, 1990 - 1993. Clipper, VAX/Cobol.

CAVISA (glass factory), Guatemala, Central America

Systems Analyst, 1987 - 1990, RM/Cobol.

SEADCO (consulting), Guatemala, Central America

Programmer, 1985 - 1986, MS/Cobol

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