Sergio S.
Modernization Integration Expert: Mainframe, Containers, Java, COBOL
Highly skilled systems architect and developer with more than 40 years of experience designing, developing, deploying and integrating applications, from old single platform “green-screen” to multi-tier / distributed systems. Business experience in manufacturing, accounting, distributing, payroll, finance and TELCO: ✔ Strong knowledge of Java SE and JEE stacks, from early versions 1.x up to latest version SE 17 and JEE 10 including Spring and Spring Boot. ✔ Deep understanding of old technologies such COBOL, VSAM, JCL, IMS, DB2, IMS “green screen”, etc. This knowledge allowed me to design, code and implement integrations between new applications with legacy ones. ✔ Solid leading and mentoring skills to help and encourage individuals to maximize their productivity by applying the best practices, frameworks, libraries and technology in general. ✔ I'm always learning about new technologies and tools to ease and reduce time spent in application development and deployment. Technology by itself is worth nothing if it does not solve real world problems.
Earnings and projects
Last 6 months ÷ 6
Last 6 months: $53k
Billed in all: $623,454$623k
$26k in the last 6 months
Across 76 contracts
Earnings, last 30 days
Skill rankings: Top 0.57% in MySQL
Top 1% in 6 of 11 skills, ranked by MRR among everyone on Upwork with the skill.
- COBOL51 freelancers · 🇬🇹 #1Top 6%🇬🇹#1 of 1
- #5Relational Database218 freelancers · 🇬🇹 #1Top 2%🇬🇹#1 of 1
- #7Database Administration797 freelancers · 🇬🇹 #1Top 0.88%🇬🇹#1 of 1
- #15Spring Framework880 freelancers · 🇬🇹 #1Top 2%🇬🇹#1 of 2
- #16System Administration1,828 freelancers · 🇬🇹 #1Top 0.88%🇬🇹#1 of 4
- #22Database Design2,161 freelancers · 🇬🇹 #1Top 1%🇬🇹#1 of 1
- #39Kubernetes3,351 freelancers · 🇬🇹 #1Top 1%🇬🇹#1 of 2
- #41Angular6,816 freelancers · 🇬🇹 #1Top 0.60%🇬🇹#1 of 4