# Y.S. ("Ramki") Ramakrishna

> Views expressed here are my own and personal, certainly not that of anyone else, including any former, current, or future employers.

Location: Pleasanton, California, United States
Profile: https://flows.cv/ys

Link to Google Scholar Page: https://scholar.google.com/citations?user=0Qb4sfwAAAAJ&hl=en

Member of the AWS Corretto team.

Formerly, the Engineering Manager for Twitter's JVM Team, and a senior platform & infrastructure engineer at Twitter working on JVM and performance optimization. Previously, senior engineer (and tech lead) in Dynamic Memory Management, Core JVM (HotSpot Java Virtual Machine) at Sun Microsystems and, through acquisition, at Oracle.

Formerly conducted research in formal verification and model checking of concurrent systems at SUNY Stony Brook, Aalborg University (Denmark), and at Tata Institute of Fundamental Research (TIFR, Bombay, India).

Education:
    - Ph.D. (Elec. & Comp. Eng.), UC Santa Barbara
    - B.Tech, (Elec Eng), IIT Kanpur, India

Specialties: Virtual machines and runtimes, Dynamic memory management,
Concurrency and synchronization,
Performance modeling and optimization,
Optimization of high-dimensional systems using statistical machine learning,
Formal methods, Formal Verification, Model Checking,
Automatic Theorem Proving, Discrete Algorithms,
Automata Theory, including Real-Time (and Omega) Automata;
some interest in Automatic Control Theory and in particular in Robust Control.

## Work Experience
### Principal Engineer (Languages & Runtimes) @ Amazon Web Services (AWS)
Jan 2022 – Present | Santa Clara, California, United States
JVM Engineering, AWS Corretto, OpenJDK, Generational Shenandoah GC and related.

### Engineering Manager @ Twitter
Jan 2020 – Jan 2022 | San Francisco, California, United States
Manager #TwitterVMTeam
Release, QA, Maintenance & Support for JDK 8 and JDK 11, including Graal JIT in both major versions; performance analysis and tuning assistance & consultation; planning and driving major version migration from JDK 8 to JDK 11, including addressing API changes, designing processes, implementing tooling at scale, addressing performance regressions, tracking progress metrics, and migration sequencing and logistics across a large set of microservices with many million lines of code. Team planning, coordination, documentation, code reviews, technical design reviews.
Hiring, summer interns, mentoring, R&D projects & incubation, technology transfer from research.

### Staff Software Engineer @ Twitter
Jan 2014 – Jan 2020 | San Francisco, California, United States
HotSpot JVM; garbage collection; performance, [ML-based] JVM and systems optimization.

### Principal Engineer (Software) @ Workday
Jan 2011 – Jan 2014 | Pleasanton, California, United States
Worked on various technologies underlying the company's SaaS product(s).

### Principal Member of Technical Staff @ Oracle
Jan 2010 – Jan 2011 | Santa Clara, California, United States
(Sun Microsystems was acquired by Oracle)

Java virtual machine, dynamic memory management, performance tuning and analysis.

### Senior Staff Engineer @ Sun Microsystems
Jan 2002 – Jan 2010 | Santa Clara, California, United States
Java virtual machines (HotSpot, ExactVM), runtime systems, dynamic memory management, concurrent programming, performance analysis and optimization, synchronization.

### Staff Engineer @ Sun Microsystems
Jan 1999 – Jan 2002 | Cupertino, California, United States
Concurrent programming for the JVM, Garbage Collection, Concurrent Garbage Collection, Performance Analysis and Optimization.

### Member of Technical Staff @ Sun Microsystems
Jan 1997 – Jan 1999 | Menlo Park, California, United States
Solaris HA/DB, JVM runtime (ExactVM), Synchronization in the JVM, Patented technique for synchronization in Java.

### Post-Doctoral Research Associate @ SUNY Stony Brook
Jan 1995 – Jan 1997 | Stony Brook, New York, United States
Concurrency, Verification, Process Algebra, Model Checking

### Fellow, Theoretical Computer Science @ Tata Institute of Fundamental Research
Jan 1994 – Jan 1995 | Mumbai, Maharashtra, India
Teaching graduate classes and Research in Logics and Algebras of Concurrency, Verification, Temporal Logic, Model Checking, Omega Automata

### Post-Doctoral Research Associate @ Aalborg University, Denmark
Jan 1993 – Jan 1994 | Aalborg, North Jutland, Denmark
Real-time process algebras and their decision problems.

### Doctoral Student, Electrical and Computer Eng @ University of California at Santa Barbara
Jan 1988 – Jan 1993 | Goleta, California, United States
Graduate work in Distributed Systems, Queueing Theory, Formal Verification, Algorithms. Taught undergraduate classes in EE and CS. Research in Temporal Logics, Interval Logics, Logics of Concurrency and related decision problems and their complexity.

### Research Engineer, Electrical Engineering @ Indian Institute of Technology, Kanpur
Jan 1986 – Jan 1988 | Kanpur, Uttar Pradesh, India
High speed optical communication networks, hardware and firmware for transceivers for local area networks, communication protocols.


## Education
### Doctor of Philosophy - PhD in Electrical and Computer Engineering
UC Santa Barbara

### Bachelor of Technology - BTech in Electrical Engineering
Indian Institute of Technology, Kanpur


## Contact & Social
- LinkedIn: https://linkedin.com/in/ysramakrishna
- Portfolio: http://blogs.oracle.com/ysr
- Portfolio: http://twitter.com

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Source: https://flows.cv/ys
JSON Resume: https://flows.cv/ys/resume.json
Last updated: 2026-04-12