Skip to content
BackNov 7
Freddy R.
Upwork badge

Freddy R.

JVM Modernization | Legacy Java to High-Performance Scala

Is your legacy Java monolith slowing down your deployments or driving up cloud costs? I help companies modernize their tech stack using Scala, Cats Effect, and Akka/Pekko to build resilient, functional systems that scale. Moving from Java to Scala isn’t just a syntax change—it’s a performance shift. I specialize in the "Strangler Pattern," allowing you to migrate critical modules into high-performance microservices without interrupting your production environment. Why work with me? - Pure Functional Expertise: I leverage Cats and Cats Effect to build type-safe, asynchronous systems that eliminate entire classes of runtime bugs. - High-Concurrency Mastery: Using Akka and Pekko, I design actor-based systems capable of handling massive throughput and real-time data processing. - Modern Data Stack: Deep experience with Kafka for event-streaming and Apache Pinot for real-time analytics. - Cloud Optimization: I don't just write code; I tune the JVM. I’ve helped clients slash GCP/AWS spend by optimizing resource allocation and implementing smart autoscaling. A "Big Tech" partner for your US team: Based in the EU, I provide a strategic time-zone overlap. I can build while your US team sleeps and be available for syncs during your morning—creating a high-velocity, 24-hour development cycle.

🇳🇱Amsterdam, Netherlands$60/hr100% JSS4.57 (2)Since Feb 2020

Earnings and projects

MRR
$3.9k

Last 6 months ÷ 6

World#8,408 / 412k
🇳🇱Country#22 / 1,538
Revenue, last 30 days
$4.7k

Last 6 months: $23k

World#6,277 / 412k
🇳🇱Country#20 / 1,538
Total earnings
$96k

Billed in all: $100k

World#40,828 / 412k
🇳🇱Country#110 / 1,538
Per project
$19k

$23k in the last 6 months

World#6,308 / 412k
🇳🇱Country#19 / 1,538
Projects, last 6 months
1
0% fixed100% hourly
World#128,095 / 412k
🇳🇱Country#346 / 1,538
Projects in all
5

Across 8 contracts

0% fixed100% hourly
World#266,044 / 412k
🇳🇱Country#935 / 1,538

Earnings, last 30 days

$100k+$4.7k earned in the last 30 daysBilled in all, before Upwork's fee · drag across the chart to see what was earned in any stretch
$95.0k$97.5k$100.0k$102.5kOct 8Oct 23Nov 7

Skill rankings: #1 in 1 skill of 14

Rarest: top 2% in Database, of 3,249. Ranked by MRR among everyone on Upwork with the skill.

  1. 1Play Framework33 freelancers · 🇳🇱 #1Top 3%
  2. #12Scala215 freelancers · 🇳🇱 #1Top 6%
  3. #64Apache Kafka981 freelancers · 🇳🇱 #1Top 7%
  4. #73Database3,249 freelancers · 🇳🇱 #1Top 2%
  5. #83Database Design2,161 freelancers · 🇳🇱 #2Top 4%
  6. #105Software Architecture & Design1,465 freelancers · 🇳🇱 #2Top 7%
  7. #174Kubernetes3,351 freelancers · 🇳🇱 #2Top 5%
  8. #182Git5,766 freelancers · 🇳🇱 #2Top 3%