About me

I am a software engineer with over ten years of experience creating robust enterprise web applications. I have founded two SaaS-based startups, one of which has been acquired. Currently, I am pursuing my Master's in the Data Systems Group at the University of Waterloo.

Github    Linkedin    david.rui at uwaterloo.ca


I'm particularly interested in doing research within the field of Data Systems, focusing on scalable data structures and algorithms for graph databases.

Kùzu DB - University of Waterloo (2023 - 2023)

Worked on Kùzu's core system, a state-of-the-art open-source graph database written in C++. Developed the testing framework, a scripting language for end-to-end and parallel testing, and implemented a parquet writer. (see my contrib here)

SAIN Lab (Security and Artificial Intelligence Lab) (2021 - 2022)

Performed literature review on graph network papers, developed experiments with graph influence functions, subgraph sampling, differentiable neural architecture search for graphs (AutoML), and knowledge distillation.


Master's degree, Mathematics and Computer Science - University of Waterloo (2024 - 2026)

Bachelor of Engineering with Highest Distinction, Software Engineering - Ontario Tech University (2020 - 2024)


2023 – Undergraduate Research Fellowship (URF) - University of Waterloo

2021 – Undergraduate Student Research Fellowship (USRF) - Ontario Tech University

Industry Experience

ADVFN (2022 - 2023)

ADVFN (LSE:ADV) (Advanced Financial Information) offers stock market information across 12 different countries. I was responsible for leading and implementing the entire website for the Korean market. I also engineered and maintained a high-performance Scanner tool on Ruby on Rails and C/C++.

Iris Digital Wealth (2018 - 2020)

As a co-founder, I developed an enterprise-level CRM application for financial advisors in Ruby on Rails, and a highly scalable cloud structure on AWS services (EC2, ECS, EKR, RDS, S3, ElastiCache, Lambda).

Liberta Global (2016 - 2017)

Developed trading algorithms in Python.

Avante (2014 - 2016)

Joined a startup as CTO at the seed stage. After raising a round of $24M, I was responsible for hiring and leading a team of software engineers, designers and QAs.

XP Securities (2014)

I led a small team to develop a novel onboarding experience for new accounts.

Bolsa Financeira (2010 - 2013)

Founded my first SaaS-based startup, building from scratch a distributed real-time scanner in erlang, ruby and C shared libraries. Acquired by L&S holding, a subsidiary of XP Inc (NYSE:XP)

My Projects


I spent two years in the military.