Hey! I am

Stefan Vercillo

I'm an asipring

About

About Me

I'm a software engineer and varisty soccer player, passionate about using technology to create lasting impact on society.

Over 0 lines of code written professionally

Download CV

Worked as a developer for the following companies:

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Blog

Technical Blog Posts

Deep dives into software engineering, distributed systems, and performance optimization

NEW

Making Large Flink Range Joins Cheap with B+Tree State

How we built a memory-efficient B+Tree state backend on top of Flink, enabling large-scale streaming joins with sorted output, secondary indexes, and KNN queries—reducing infrastructure costs 1000x.

COMING SOON

More Technical Posts Coming Soon

Stay tuned for more deep dives into distributed systems, streaming architectures, and performance optimization techniques. Topics will include streaming systems, database internals, and scalable architecture patterns.

Projects

Personal Projects

The majority of my work is not open-sourced, however here's a few projects to showcase some of my skills!

Relational Query Optimizer

Click above to see the repo!

Database Transaction Scheduler

Click above to see the repo!

DAG Execution Engine

Click above to see the repo!

Real Time Operating System Testing Framework

Click above to see the repo!

Path Finding Visualization

Click above to see the demo!

LeetCode Algorithms

Algorithms Questions Solved

Education

2018-2023 expected

Bachelor of Computer Engineering

University of Waterloo
Relevant Courses:
  • Systems Programming & Concurrency (97%)
  • Programming for Performance (96%)
  • Programming Fundamentals (95%)
  • Algorithms & Data Structures I/II
  • Distributed Computing
  • Computer Security
  • Database Sys Implementation
  • Operating Systems

IB Diploma Graduate

Michael Power HS

Achieved an average of 94% in the International Baccalaureate program.

Experience

September 2022 - Present

Senior Software Engineer / Intern

Palantir -- Streaming
  • Built a B+ Tree state module on top of Flink, enabling large-scale streaming interval and KNN joins with sorted output, secondary indexes, and memory-efficient eviction ($7M->$1K annual infra cost reduction in first production join instance)
  • Designed a parallelized Kafka archival module that boosted throughput 75x and enabled recovery from multi-terabyte backlogs within minutes, preventing critical disk outages and data loss across all production streaming pipelines.
  • Achieved up to 100× faster stream backlog processing by building and orchestrating a Spark job that reorganized multi-terabyte Kafka archives into a virtual bucket layout, eliminating partition skew and I/O bottlenecks.
  • Built a custom parallel Flink ingest from virtual buckets, ensuring per-key ordering, fairness, and dynamic load balancing; reduced replay times from months to hours while maintaining consistency and fault tolerance guarantees.
  • Developed an async request batching layer to reliably support high-latency, expensive operations at scale, enabling real-time LLM-based intelligence enrichment and AI transformations on high-volume video, audio, and imagery streams.
  • Innovated streaming ingest method utilizing auto-scaling containers for flexible data population, enabling edge use cases such as live audio calls that seamlessly integrate with a live AIP-driven recommendation engine
  • Implemented metrics-driven dynamic scaling, ensuring Flink workloads maintain performance while minimizing unnecessary compute costs.
May 2022 - August 2022

Software Engineer Intern

Twitter -- Kernel and Encryption Team
  • Deployed Booster, a high-performance init-ram-fs generator across Twitter production Linux machines, reducing early-stage boot time by 15% while supporting full-disk encryption with TPM/network-bound unlock.
December 2021 - May 2022

Early Software Engineer

Federato AI
  • Engineered a secure multi-tenant secrets platform using HashiCorp Vault with webhook sidecars and per-client VPC isolation, automating VPN provisioning and access controls to centralize governance and strengthen compliance at scale.
  • Designed and centralized continuous deployment workflows with GitOps-driven ArgoCD, enabling scalable, automated rollouts across client clusters and reducing operational overhead while ensuring consistent, auditable deployments.
January 2021 - May 2021

Quantitative Developer

TradeLogiQ / Omega ATS
  • Engineered a high-performance ingestion layer for TSX exchange data, ensuring consistent, real-time market data delivery.
  • Optimized UDP retransmission in C++, cutting latency by 70% and improving order book accuracy under packet loss.
December 2020 - May 2021

Software Engineer

Enso Connect
May 2020 - September 2020

Quantitative Developer Intern

TD Bank
September 2019 - January 2020

Software Engineer

Sky View Suites
January 2019 - May 2019

Software Engineer Intern

Ford Motor Company

Recommendations

Luke Mckim

TradeLogiq
“Stefan’s understanding of concurrency and socket-programming was impressive over the term. Above all his ability to continuously think in terms of optimizing resource utilization and algorithmic latency helped him strive in this position.” -Senior Engineer

Francois Gouelo

Enso Connect
“Stefan’s interpersonal skills created a collaborative environment of sharing of ideas” … “His strong understanding of software fundamentals, convention, and modern infrastructure was demonstrated during his time at Enso.” - CEO / Founder

Extracurricular

Varsity / Semi-Pro Soccer

    Leadership, mental toughness and communication developed playing for the University and with North Mississauga League One, training 5-8 times a week playing against the best in Ontario

Piano Performance

    Creativity and expressiveness developed through piano performance at the highest level achieve RCM level 10 certification

Math / Programming Tutor / Swim Instructor

    Developed strong language skills being able to communicate technically complex in collaborative setting

Skills

Proficiency

Java

95%
75%
2018
80%
2021

C++

90%
50%
2018
60%
2021

Python

95%
33%
2018
60%
2021

SQL

90%

JavaScript

85%

C

80%

Terraform

95%

PHP

85%

HTML/CSS

75%

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Contact

Contact Me

For professional inquires or information about a job opening, contact me via one of the methods below