Dan is available for hire
Hire DanDan Lester
Verified Expert in Engineering
Software Developer
Cambridge, United Kingdom
Toptal member since March 23, 2022
Bio
Dan has been a software developer and entrepreneur for over 15 years, building and exiting various companies worth millions. Dan worked in the financial industry and brings an unrivaled understanding of the business needs and culture of a wide range of workplaces where roles have included CTO, COO, founder, machine learning developer, and quantitative research analyst. He enjoys the technical challenge of contracting and finding inspiration for his independent open-source projects.
Portfolio
Ideonate
Python, Open Source, Docker, Kubernetes, JavaScript, React, REST, Node.js...
Provance Ltd
Python, HTML, JavaScript, CSS
Quansight
Python, Terraform, Amazon Web Services (AWS), Kubernetes, Google Cloud, Azure...
Experience
- Python - 14 years
- JavaScript - 10 years
- Amazon Web Services (AWS) - 10 years
- Google Cloud - 4 years
- React - 4 years
- Kubernetes - 3 years
- Terraform - 2 years
- Azure - 2 years
Availability
Part-time
Preferred Environment
MacOS, Visual Studio Code (VS Code), Slack, Python, GitHub, Amazon Web Services (AWS)
The most amazing...
...company I've co-founded as a CTO was Conversocial, which grew to a 100-person business and was acquired by Verint for $50 million in 2021.
Work Experience
Founder
2019 - PRESENT
Ideonate
- Developed and maintained a range of open-source technologies to help data scientists present results to non-technical stakeholders.
- Built upon and contributed back to established open-source projects such as JupyterHub.
- Built and published JupyterLab extensions in TypeScript.
Technologies: Python, Open Source, Docker, Kubernetes, JavaScript, React, REST, Node.js, Data Visualization, Machine Learning, Artificial Intelligence (AI), CTO
Python Developer
2022 - 2022
Provance Ltd
- Mapped out the required business and manufacturing processes and designed automation involving robots.
- Advised on technology stack (choosing Python/React) based on the client's medium-term needs and the robot's technical features.
- Built a Python back end and React front end, deploying within a closed factory environment.
Technologies: Python, HTML, JavaScript, CSS
Developer and Product Manager
2021 - 2022
Quansight
- Built an open-source product, QHub, enabling clients of US-based Quansight to roll out a JupyterHub data science platform on their private clouds.
- Ensured compatibility between different clouds including AWS, Google Cloud, Azure, as well as on-premises Kubernetes clusters.
- Developed tools for data scientists through my own open-source dashboarding solution, which I integrated into Quansight's platform after they became aware of my expertise.
Technologies: Python, Terraform, Amazon Web Services (AWS), Kubernetes, Google Cloud, Azure, APIs, API/Services Architecture, REST, Data Visualization, Full-stack
Software Development Contractor
2020 - 2021
Arcturus
- Developed data pipelines to process raw climate change data from Excel and other data sources to build an innovative climate risk model for the financial services industry.
- Coordinated pipelines with Azure Data Factory and included automated data cleaning functionality written in Python.
- Expanded on a GraphQL API to serve the data to a web app.
Technologies: Python, Azure, Azure Data Factory (ADF), SQL, Azure Synapse, API/Services Architecture, Node.js, Artificial Intelligence (AI)
Co-founder, COO, and CTO
2009 - 2021
Conversocial
- Co-founded this VC-funded international SaaS business, which Verint (Nasdaq: VRNT) acquired for $50 million in 2021.
- Hired a development team to help build the initial versions of the product.
- Assisted in acquiring customers including Hertz, Sephora, Tesco, McDonalds, and more.
Technologies: Python, Amazon Web Services (AWS), APIs, API/Services Architecture, REST, Full-stack, CTO
Machine Learning Developer
2018 - 2019
Granta Innovation
- Guided an early-stage startup in developing deep learning computer vision models to build screening tools for prostate cancer based on MRI images.
- Prototyped PyTorch and fast.ai pipelines in Jupyter Notebooks (Python), taking irregular CSV and DICOM files to produce an image segmentation CNN model.
- Built a custom JavaScript application for in-house image segmentation and annotation.
Technologies: Python, PyTorch, Computer Vision, JavaScript, Full-stack, Machine Learning, Artificial Intelligence (AI)
Founder
2014 - 2018
WP-Glogin.com
- Built and operated this business from the ground up to reach a total of $2 million revenue over four years, including the final sale of the business assets to a US-based company.
- Developed a suite of complementary WordPress plugins allowing customers to build intranets.
- Sold to high-profile enterprise customers ranging from established brands and public companies to leading universities and some of the world’s best-known startups.
Technologies: PHP, JavaScript, REST, Excel Add-ins, Full-stack, CTO
Co-founder and CTO
2007 - 2012
iPlatform
- Co-founded this agency business which helped large brands make use of Facebook for marketing purposes during the time of its explosive growth.
- Developed social competitions and other innovative Facebook apps for global customers, including McDonald's, The Economist, Google, and Tesco, and acted as specialist sub-contractors for leading media agencies.
- Served as CTO. Maintained oversight of all technical decisions and remained as lead developer for core products and libraries such as our Facebook API integrations and reusable app platform.
- Received frequent recommendations directly by Facebook and was appointed as their first official UK development partner.
Technologies: Python, Django, JavaScript, Facebook API, REST, Full-stack, CTO, PHP
Quantitative Research Analyst
2004 - 2007
Citi
- Maintained UNIX-based infrastructure for delivering real-time pricing and risk analytics to trading desks in the investment bank's fixed-income division.
- Created Excel-based prototypes in close consultation with in-house traders, to experiment with new UIs and reporting systems.
- Contributed to documentation and processes to simplify and streamline support requirements for the wide-ranging collection of systems used within the bank.
Technologies: C++, Perl, Unix, Excel Add-ins
Quantitative Developer
2001 - 2004
Advanced Portfolio Technologies
- Developed a quadratic stock optimizer and core risk model software.
- Built reporting tools, both GUI- and script-based, to calculate risk analytics for traders and back-office staff.
- Discussed with traders, fund managers, and IT departments to establish technical requirements.
Technologies: Delphi, Excel VBA, Windows, Java, Perl, Excel Add-ins, Full-stack
Experience
ContainDS Dashboards
An open-source dashboard publishing solution for data science teams to share results with decision-makers.
Data scientists typically build models and reports in a Jupyter Notebook, adding interactive controls using other open-source frameworks, but then they have no easy way to share their models with others in the organization.
ContainDS sits on top of JupyterHub, allowing granular access to be granted to other users so they can interact with the deployed dashboard without needing to understand code.
Data scientists typically build models and reports in a Jupyter Notebook, adding interactive controls using other open-source frameworks, but then they have no easy way to share their models with others in the organization.
ContainDS sits on top of JupyterHub, allowing granular access to be granted to other users so they can interact with the deployed dashboard without needing to understand code.
Jupyter Innotater
http://jupyter-innotater.rtfd.ioA JupyterLab extension for data scientists to easily annotate their training data, including image bounding boxes, inline within their Jupyter Notebook.
Innotater’s flexible Python API allows easy selection of interactive controls to suit datasets, accessible in the same way developers interact with them.
Innotater’s flexible Python API allows easy selection of interactive controls to suit datasets, accessible in the same way developers interact with them.
nb2xls
https://github.com/ideonate/nb2xlsConvert Jupyter Notebooks to Excel Spreadsheets (XLSX), through a new ‘Download As’ option or via nbconvert on the command line.
Respects markdown and tables such as Pandas DataFrames. Also exports image data such as Matplotlib output.
This allows you to share your results with non-programmers such that they can still easily play with the data.
Respects markdown and tables such as Pandas DataFrames. Also exports image data such as Matplotlib output.
This allows you to share your results with non-programmers such that they can still easily play with the data.
Education
1997 - 2001
Master's Degree in Mathematics
University of Oxford - Oxford, UK
Skills
Libraries/APIs
React, Facebook API, Node.js, Plotly.js, PyTorch
Tools
Jupyter, Slack, GitHub, Terraform, MATLAB
Languages
Python, JavaScript, Excel VBA, SQL, PHP, HTML, CSS, TypeScript, C++, Perl, Delphi, Java
Paradigms
API/Services Architecture, REST, DevOps
Frameworks
Cypress, Django, Electron
Platforms
Amazon Web Services (AWS), Kubernetes, Azure, Visual Studio Code (VS Code), MacOS, Azure Synapse, Linux, Docker, Unix, Windows
Storage
Google Cloud
Other
GitHub Actions, APIs, Data Visualization, Dashboards, Full-stack, CTO, Azure Data Factory (ADF), FastAPI, Excel Add-ins, Cloud, Machine Learning, Open Source, Computer Vision, Artificial Intelligence (AI)
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