Dae is available for hire
Hire DaeDae Choi
Verified Expert in Engineering
Software Developer
Palmetto, FL, United States
Toptal member since October 3, 2018
Bio
Dae pairs three decades of engineering and technology leadership — including CTO of a global multi-strategy hedge fund — with current, hands-on depth in Go and Rust. His recent focus is cloud-native and AI/LLM infrastructure: multi-region database orchestration on Kubernetes, real-time event-driven data pipelines, and an open-source LLM tokenizer on crates.io and PyPI. He still builds what he designs.
Portfolio
Domanic, LLC
Go, SCADA, Linux, PostgreSQL, MongoDB, JavaScript, SQL Stored Procedures...
Crystal Corp.
Go, SQL, PostgreSQL, Rust, Kubernetes, Amazon Web Services (AWS), Python, Git...
Sifchain Finance
MongoDB, Python, PostgreSQL, Amazon Web Services (AWS), Kubernetes, Go...
Experience
- SQL - 20 years
- Python 3 - 15 years
- Hedge Funds - 15 years
- PostgreSQL - 8 years
- ETL - 6 years
- AWS Cloud Architecture - 5 years
- Rust - 4 years
- Large Language Models (LLMs) - 3 years
Preferred Environment
Linux, Go, Apache Kafka, Helix, MacOS, Rust, Python, Kubernetes, PostgreSQL, Amazon Web Services (AWS)
The most amazing...
...project I've built from scratch is the front-to-back trading platform behind a hedge fund's growth from $2 billion to $20 billion.
Work Experience
Principal
2016 - PRESENT
Domanic, LLC
- Provided infrastructure and architecture reviews plus security operations monitoring for the New York MTA — Metro-North, NYC Transit, Bridges and Tunnels, and LIRR — improving response time and reducing technology expenditures.
- Implemented SOC 2 Type II controls — proactive monitoring, severity-based alerts, and audit trails — using CloudWatch, CloudTrail, GuardDuty, SNS, and Lambda triggers; added AWS X-Ray tracing for data flows and business exceptions.
- Offloaded Django performance bottlenecks to AWS Lambda and API Gateway, migrated user identity management to Amazon Cognito, and moved an idling EC2 workload to Fargate — cutting costs while improving availability.
Technologies: Go, SCADA, Linux, PostgreSQL, MongoDB, JavaScript, SQL Stored Procedures, AWS Cloud Architecture, CI/CD Pipelines, SQL, Git, ETL, Docker, Data Engineering, Architecture, Stakeholder Management, Tableau, Microsoft Power BI, Amazon Web Services (AWS), Back-end, Swagger, Technical Leadership, People Management, REST APIs, Full-stack, Web Development, Data Build Tool (dbt), Data Modeling, Star Schema, Data Transformation, Algorithms, Scraping, Web Scraping, HTTP, JSON, AWS Lambda, Amazon EKS, Amazon Elastic Container Service (ECS), Amazon S3 (AWS S3), Amazon Simple Notification Service (SNS), Amazon Simple Queue Service (SQS), Grafana, Relational Database Services (RDS), Data Analysis, Data Strategy, Data Analytics, Data Management, MDM, Data Structures, Jupyter, NumPy, GitHub, Quantitative Modeling, Pandas, Hedge Funds, Python 3, Enterprise Cybersecurity
Lead Engineer (via Toptal)
2022 - 2024
Crystal Corp.
- Architected and implemented a cloud-native, multi-region PostgreSQL orchestrator (control plane in Go and Rust) that provisions and scales clusters on client demand.
- Led proofs of concept, customer engagements, and product evangelization while managing the day-to-day work of the engineering team.
- Built automated backup/restore, AI-driven performance tuning, and usage metering for client PostgreSQL clusters — production services in Go and Rust on Kubernetes across the AWS ecosystem.
Technologies: Go, SQL, PostgreSQL, Rust, Kubernetes, Amazon Web Services (AWS), Python, Git, ETL, Timescale, C++, Data Pipelines, AWS Cloud Architecture, Docker, Data Engineering, Data Architecture, Big Data Architecture, Architecture, Back-end, Swagger, Technical Leadership, Product Management, People Management, REST APIs, Full-stack, Web Development, Data Modeling, Star Schema, Data Transformation, Prometheus, Apache Spark, Amazon SageMaker, API Observability, Observability Tools, SDKs, Algorithms, Scraping, Web Scraping, Concise Binary Object Representation (CBOR), HTTP, JSON, AWS Lambda, Amazon EKS, Amazon Elastic Container Service (ECS), Amazon S3 (AWS S3), Amazon Simple Notification Service (SNS), Amazon Simple Queue Service (SQS), Identity & Access Management (IAM), Data Visualization, Grafana, Web Crawlers, Microservices, Distributed Systems, Large-scale Distributed Systems, Relational Database Services (RDS), Data Analysis, Data Strategy, Data Structures, GitHub, Python 3
Head of Data Services (via Toptal)
2020 - 2022
Sifchain Finance
- Led the Data Services Group, owning data flows across the back end, front end, external partners, and market-data services.
- Designed and built a low-latency, high-throughput engine for real-time trade and market-data processing in Rust and Go, on Kafka and TimescaleDB.
- Developed crypto-economic programs, including trading competitions, margin, liquidity mining, and token rewards.
Technologies: MongoDB, Python, PostgreSQL, Amazon Web Services (AWS), Kubernetes, Go, Apache Kafka, Timescale, SQL, Git, ETL, Rust, Data Pipelines, AWS Cloud Architecture, Docker, Data Engineering, Data Architecture, Big Data Architecture, Architecture, Business Requirements, Back-end, Swagger, Technical Leadership, Product Management, People Management, Elasticsearch, REST APIs, Web Development, Data Build Tool (dbt), Data Modeling, Snowflake, Star Schema, Data Transformation, Databricks, PySpark, Apache Spark, Amazon SageMaker, API Observability, Observability Tools, SDKs, Algorithms, Scraping, Selenium, Web Scraping, Concise Binary Object Representation (CBOR), HTTP, JSON, AWS Lambda, Amazon EKS, Amazon Elastic Container Service (ECS), Amazon S3 (AWS S3), Amazon Simple Notification Service (SNS), Amazon Simple Queue Service (SQS), Identity & Access Management (IAM), Crypto, Data Visualization, Grafana, Blockchain, Web3, Trading, Algorithmic Trading, Trading Systems, Cryptocurrency, Microservices, Distributed Systems, Large-scale Distributed Systems, Relational Database Services (RDS), Data Analysis, Data Strategy, Data Analytics, Data Structures, Jupyter, NumPy, GitHub, Quantitative Modeling, Pandas, Python 3
Software Consultant
2017 - 2022
Standard General, LP
- Developed a position and trade reconciliation system between Advent Geneva and the firm's OMS.
- Created and supported various reports for trades and historical returns.
- Built an investor database and provided support for multiple funds.
Technologies: Microsoft Excel, Advent Geneva, SQL, C#, SQL Stored Procedures, Python, Git, ETL, Kubernetes, AWS Cloud Architecture, Docker, Data Architecture, Architecture, Business Requirements, Microsoft Power BI, Amazon Web Services (AWS), Back-end, Swagger, Technical Leadership, People Management, Full-stack, Web Development, Data Modeling, Star Schema, Data Transformation, Databricks, PySpark, Apache Spark, Observability Tools, SDKs, Workflow Automation & System Integration, Algorithms, Scraping, Web Scraping, HTTP, JSON, AWS Lambda, Amazon EKS, Amazon Elastic Container Service (ECS), Amazon S3 (AWS S3), Amazon Simple Notification Service (SNS), Amazon Simple Queue Service (SQS), Azure, Identity & Access Management (IAM), Data Visualization, Grafana, Blockchain, Microservices, Distributed Systems, Relational Database Services (RDS), Data Analysis, Data Strategy, Data Analytics, Data Structures, NumPy, GitHub, Quantitative Modeling, Pandas, Hedge Funds, Python 3
VP of Engineering
2019 - 2021
NexHealth
- Ingested and orchestrated healthcare records from dental providers nationwide into a centralized data warehouse, enabling real-time, unified patient care.
- Developed Sync Agents integrating data across 14 EMRs, including CareCloud, Curve, Dentrix, Denticon, Dr.Chrono, eClinicalWorks, EagleSoft, OpenDental, and Dolphin — normalizing records from the dental industry's most fragmented platforms.
- Optimized processing of 8+ million patient records from hours to seconds. Introduced DevOps practices and automated demand-based scaling and provisioning of cloud resources.
- Managed and trained customer success managers (CSMs) and engineers to handle complex customer inquiries.
Technologies: Python, SQL, ETL, Node.js, Data Structures, Algorithms, NumPy, GitHub, Pandas, Python 3
VP of Engineering
2018 - 2019
LoanStreet
- Improved operational efficiency, scalability, and reliability. Introduced DevOps practices with CloudFormation and refactored Makefiles and Git hooks to trigger testing and continuous deployment via Travis CI.
- Devised Lambda/S3 triggers to scan for viruses or malware on incoming client transaction files to quarantine data and alert the support staff.
- Led the front and back-end development with coding best practices and guidelines. Actively reviewed code changes in Git pull requests throughout the day to ensure high code quality and best practices.
- Created a high-performance culture by building a collaborative team. Inherited a team with no discernible work process and instilled the Agile software development methodology.
Technologies: AWS CloudFormation, Python, React, PostgreSQL, JavaScript, ETL, SQL Stored Procedures, Unix Shell Scripting, SQL, Git, Kubernetes, Data Pipelines, AWS Cloud Architecture, Docker, Data Engineering, Data Architecture, Big Data Architecture, Architecture, Business Requirements, Amazon Web Services (AWS), Back-end, Swagger, Technical Leadership, Product Management, Flask, People Management, Apache Kafka, Elasticsearch, REST APIs, Full-stack, Web Development, Data Build Tool (dbt), Data Modeling, Snowflake, Dimensional Modeling, Star Schema, Data Transformation, Observability Tools, SDKs, Workflow Automation & System Integration, HTTP, JSON, AWS Lambda, Amazon EKS, Amazon S3 (AWS S3), Amazon Simple Notification Service (SNS), Amazon Simple Queue Service (SQS), TypeScript, Identity & Access Management (IAM), Web Crawlers, Microservices, Distributed Systems, Relational Database Services (RDS), Data Analysis, Data Strategy, Data Analytics, Data Structures, Algorithms, Algorithmic Trading, GitHub, Quantitative Modeling, Pandas, Python 3
Software Consultant
2016 - 2017
Reservoir Capital, LP
- Developed a solution to extract live data from multiple QuickBooks company files and generate consolidated Excel reports in real time.
- Integrated with the QuickBooks SDK to read multiple company files concurrently, eliminating the manual export/import cycle previously run per entity.
- Delivered real-time reporting of cash balances, expenses, and inter-entity consolidation on Microsoft SQL Server and Node.js for fund operations.
Technologies: Intuit QuickBooks, Microsoft SQL Server, Node.js, Go, JavaScript, ETL, SQL, Git, Kubernetes, Hedge Funds, Data Pipelines, Docker, Architecture, Business Analysis, Business Requirements, Stakeholder Management, Tableau, Microsoft Power BI, Amazon Web Services (AWS), Back-end, Technical Leadership, Flask, People Management, Elasticsearch, REST APIs, Data Build Tool (dbt), Data Modeling, Snowflake, Data Analytics, Dimensional Modeling, Star Schema, Data Transformation, SDKs, Automation, Workflow Automation & System Integration, Excel VBA, Selenium, HTTP, JSON, AWS Lambda, Amazon Simple Queue Service (SQS), TypeScript, Algorithmic Trading, Trading Systems, Microservices, Distributed Systems, Relational Database Services (RDS), Data Analysis, Data Strategy, Data Structures, Algorithms, Jupyter, NumPy, GitHub, Python 3
Chief Technology Officer
2003 - 2014
King Street Capital Management
- Owned the technology roadmap, budget, design reviews, and engineering standards; led implementations and collaborated with stakeholders to drive best-practice adoption and eliminate redundancy.
- Built a standardized information infrastructure supporting the full trade lifecycle across multiple asset types, underpinning the firm's growth from a $2 billion single-strategy fund to a $20 billion multi-strategy firm across four global offices.
- Formed and maintained a staffing plan that minimized costs and dependence on contractors and vendors while maximizing ROI and service levels.
- Built a secure, scalable private cloud providing resiliency and high-performance computing, plus a global network platform connecting operations across New York, London, Tokyo, and Singapore.
- Built a proprietary complex event processing (CEP) engine with an exception-driven model, triggering alerts and workflows from market events and complex scenarios while filtering out noise.
Technologies: Apache Kafka, Bloomberg API, SQL, Java, C#, PostgreSQL, JavaScript, ETL, Git, Kubernetes, Hedge Funds, Data Pipelines, Docker, Data Governance, Architecture, Business Analysis, Business Requirements, Stakeholder Management, Tableau, Microsoft Power BI, Technical Leadership, Product Management, People Management, REST APIs, Full-stack, Data Build Tool (dbt), Data Modeling, Data Warehousing, Data Analytics, Dimensional Modeling, Star Schema, Data Transformation, SDKs, Automation, Workflow Automation & System Integration, Excel VBA, Visual Basic for Applications (VBA), HTTP, JSON, Microsoft SQL Server, Azure, Trading, Algorithmic Trading, Trading Systems, Options Trading, Distributed Systems, Large-scale Distributed Systems, Data Analysis, Data Strategy, Data Management, MDM, Data Structures, Algorithms, Jupyter, NumPy, GitHub, Quantitative Modeling, Pandas, Python 3
Principal
2002 - 2003
Liberty Street Partners, LLC
- Provided the analysis, design, and implementation of a web-based portfolio analytics program for the research group at a $2.5 billion fund of a hedge fund investment manager.
- Implemented a back-office integration framework for a proprietary trading firm with 200 traders and seven different clearing firms. Automated the workflow to receive and match transactions from each firm to post changes to the firm's general ledger.
- Implemented a software and hardware pilot solution for Microsoft Global Summit (commissioned by USAID and Dell) to enable two manufacturing companies and freight forwarders to trade overseas using an electronic document exchange based on XML.
Technologies: SQL, C#, BizTalk, ETL, Architecture, Business Analysis, Business Requirements, Stakeholder Management, Microsoft Power BI, Technical Leadership, People Management, Data Modeling, Dimensional Modeling, Data Transformation, SDKs, Visual Basic for Applications (VBA), HTTP, Data Strategy, Data Management, MDM, Data Structures, Algorithms, Algorithmic Trading, Jupyter, NumPy, GitHub, Quantitative Modeling, Pandas, Python 3
Architect
2000 - 2002
Sapient, Inc.
- Implemented a subscription web portal for Moody's Investors Service, giving institutional clients access to asset-backed and RMBS performance data from the 1980s onward; owned overall site design and architecture.
- Led requirements and process design for Morgan Stanley's consolidation of its Individual Investors web portal and ClientServ account-management tool into a single web platform, producing screen flows, use cases, and functional specifications.
- Defined application architecture for Bessemer Trust — component layering, naming conventions, deployment strategy — incorporating security requirements and support for parallel development across the team.
- Developed an enterprise web application for Goldman Sachs for secure document delivery and processing on iManage and Tumbleweed; devised the centralized framework, application management, and database synchronization strategy.
- Developed an SDK for Bear Stearns' institutional clients to interface with the firm's securities-transaction and clearance infrastructure; defined the architecture extending its single sign-on and entitlement systems via EJB.
Technologies: IIS, Active Server Pages (ASP), Visual Basic, SQL, Java, C++, ETL, Python, Git, Docker, Data Architecture, Architecture, Business Analysis, Business Requirements, Stakeholder Management, Technical Leadership, People Management, Data Modeling, Dimensional Modeling, Visual Basic for Applications (VBA), HTTP, Data Strategy, Data Structures, Algorithms, NumPy, GitHub
Architect
1994 - 1997
Intelisys, Inc.
- Designed fault-tolerant network security and system administration for an electronic-commerce message exchange.
- Architected the Cisco-based network — redundant routing, firewalling, and failover — to keep the message exchange available around the clock.
- Built message-processing components in C++ with SQL-backed persistence, serving trading-partner document exchange over the public internet.
Technologies: Cisco, IIS, C++, SQL, Architecture, Stakeholder Management, Data Modeling, Visual Basic for Applications (VBA), HTTP, Data Structures, Algorithms, GitHub
Experience
Critical Infrastructure Cybersecurity - U.S. Largest Transit System
I founded a technology startup to secure critical infrastructure in the nation's largest transportation sector against cyber threats. Spanning multiple agencies, I identified infrastructure and application vulnerabilities, improved security operations monitoring, and formulated an escalation and mitigation strategy to help safeguard 8.6 million average daily commuters.
Front-to-back Trading Platform - $2 Billion to $20 Billion Global Hedge Fund
As CTO, I built the technology department and the standardized platform that supported the firm's growth from a $2 billion single-strategy, one-office hedge fund into a $20 billion multi-strategy global firm. The platform covered the full trade lifecycle across all asset classes: research, trade capture, portfolio and position processing, risk, operations, accounting, reconciliation, reporting, and external integrations — plus a private cloud infrastructure and a proprietary complex event processing engine driving alerts and workflows from market events.
eyeMark
I authored eyeMark in Go — a real-time scanning and trend-reporting application that performed vulnerability analysis of known and unknown devices connecting from the internal corporate environment to the outside internet, assessing enterprise footprint and exposure to outside threat actors. It was built during my critical infrastructure security engagement.
riptoken - High-performance BPE Tokenizer for LLMs (Rust)
https://github.com/daechoi/riptokenI authored riptoken, a from-scratch BPE tokenizer for LLM pipelines, written in Rust with Python bindings and published to crates.io and PyPI. It is a drop-in replacement for OpenAI's tiktoken — reads the same vocabulary files, produces byte-identical output — while running 2.4×–6.5× faster single-threaded and up to 7× faster in parallel batch mode. On a 32-core server, tiktoken's p99 batch latency reaches 9.3 seconds on multilingual text due to internal cache contention; riptoken's is 777 ms. The performance comes from systems-level engineering: zero-allocation hash lookups, cache-aware merge ordering, an O(m log n) heap path for long inputs, and dense DFAs pre-compiled at build time and shared lock-free across threads. Every commit is CI-verified to be byte-identical to tiktoken, and pre-built wheels ship for CPython 3.9–3.14 across Linux, macOS, and Windows.
Education
1989 - 1993
Bachelor's Degree in Mathematics
Polytechnic University - Brooklyn, NY, USA
Skills
Libraries/APIs
React, REST APIs, NumPy, Pandas, Node.js, Bloomberg API, PySpark
Tools
Mongoose, Amazon EKS, Amazon Simple Queue Service (SQS), Jupyter, GitHub, Git, AWS CloudFormation, Tableau, Microsoft Power BI, Amazon SageMaker, Observability Tools, Amazon Elastic Container Service (ECS), Amazon Simple Notification Service (SNS), Grafana, Vim Text Editor, Advent Geneva, Microsoft Excel, Helix
Languages
Java, Python, Go, JavaScript, SQL, Python 3, Excel VBA, C#, Rust, Visual Basic for Applications (VBA), TypeScript, C++, Visual Basic, Active Server Pages (ASP), GraphQL, Snowflake
Frameworks
Swagger, .NET, Flask, Apache Spark, Selenium
Paradigms
ETL, Microservices, Agile, Dimensional Modeling, API Observability, Automation
Platforms
Apache Kafka, Amazon Web Services (AWS), Windows, Docker, Linux, Kubernetes, Databricks, AWS Lambda, Azure, Blockchain, Visual Studio Code (VS Code), MacOS
Storage
Microsoft SQL Server, MongoDB, PostgreSQL, Data Pipelines, SQL Stored Procedures, Elasticsearch, JSON, Amazon S3 (AWS S3), MySQL
Industry Expertise
Cybersecurity, Trading Systems
Other
Hedge Funds, Data Engineering, Data Architecture, Big Data Architecture, Architecture, Business Analysis, Business Requirements, Stakeholder Management, Back-end, Technical Leadership, Product Management, People Management, Full-stack, Data Modeling, Data Analytics, Data Transformation, SDKs, Algorithms, HTTP, Data Visualization, Trading, Algorithmic Trading, Distributed Systems, Large-scale Distributed Systems, Relational Database Services (RDS), Data Analysis, Data Strategy, Data Management, MDM, Data Structures, Business Continuity & Disaster Recovery (BCDR), Unix Shell Scripting, AWS Cloud Architecture, Data Governance, Data Build Tool (dbt), Data Warehousing, Star Schema, Prometheus, Workflow Automation & System Integration, Scraping, Web Scraping, Identity & Access Management (IAM), Crypto, Web Crawlers, Web3, Cryptocurrency, Options Trading, Quantitative Modeling, Large Language Models (LLMs), SCADA, IIS, Cisco, Intuit QuickBooks, BizTalk, CI/CD Pipelines, Timescale, Web Development, Mathematics, Concise Binary Object Representation (CBOR), Enterprise Cybersecurity, Performance Optimization, Open Source, OpenAI, Automated Trading Software, Cybersecurity Operations, Security
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