Sam de Freyssinet

An archive of thoughts and discoveries in the world of software development


I have been working in the computer industry since 2001. In that time I have worked on a number of exciting projects across a broad spectrum of industries. I have catalogued some of those projects here due to the brevity of their existence.

Although I will only refer to the roles I participated in across these various endeavours, almost all of the projects listed here were only possible due to a team of highly talented people that I am consistently in awe of.


Sittercity Mobile

Following the relaunch of Sittercity in November of 2013, work immediately began on the production of the new Sittercity mobile application for iOS and Android.

In addition to building out two native mobile applications that deliver the Sittercity experience to the two most popular mobile platforms, a new set of public APIs were required to support the mobile initiative.

I oversaw four technical teams building out the iOS and Android native applications, plus the design and implementation of the Sittercity Public API to support the applications. Finally the forth team worked on building out a new highly available and scalable operational platform to support the new API and other Sittercity applications.

Work is ongoing across the four projects to further enhance the application, features and infrastructure supporting the new Sittercity APIs and mobile applications. In the near future we hope to open up our APIs to allow third parties to integrate with Sittercity data.

There are four awesome discreet teams working to bring all of these products and services together. I am as always in awe of the skill and dedication of the Sittercity Engineering team.


Big Sky MMXIV from Sam de Freyssinet on Vimeo.

In March of 2014, a group of friends and I headed out to Montana in search of fresh powder on Big Sky. Big Sky Resort is one of the largest ski areas in the USA, only surpassed in scale by Whistler. Additionally, the Lone Peak at Big Sky provides the greatest vertical drop available in the country.

Using a Go Pro Hero 3 Black Edition and an iPhone 5, footage from our escapades on the mountain was shot over six days. The footage was transcoded after each days boarding. Finally after returning to Chicago, this video was cut together in Final Cut Pro X.

This was my first time shooting and editing with the Go Pro 3. The quality of the HD footage is incredible.

Rape Victim Advocates, Chicago – One Billion Rising 2014 Video

RVA OBR 2014 Video from Sam de Freyssinet on Vimeo.

The Rape Victim Advocates charity in Chicago approached me to to help them produce a video to promote their upcoming involvement in the One Billion Rising campaign. RVA had already filmed their staff talking about empowering victims of sexual abuse to speak up and seek justice. The charity needed all of the interviews to be placed into a narrative and include footage of their previous years One Billion Rising event.

All of the footage seen in this video was filmed on mobile phones. It is amazing that we can now produce promotional material quickly and easily using the devices we carry in our pockets. Over the Christmas holiday period I sat with Siân and we cut the video together in Final Cut Pro X. The narrative was already agreed upon, so the work mainly involved editing, colour correction and trying to clean up the sound which unfortunately did give away the equipment used.

It was a fun project to be involved in and I was glad to help this charity that does incredible work daily to make the lives of victims of sexual abuse better.


Sittercity 2.0

Sittercity launched a brand new experience at the end of 2013. To support the demanding new direction for the company, a completely redesigned platform was built from the ground up. Introducing new technologies across the entire stack, I was involved in numerous projects that supported the overall delivery of the new platform.

As the Vice President of Technology at Sittercity I am currently overseeing the second phase of development on our new platform. Although almost everything we do is top secret due to a fierce rivalry, I am enjoying every moment of working on this project with an incredibly talented team of engineers. Hopefully I will be able to share some more information about some of the incredible systems we have developed in the future, once we are convinced our competitors photocopiers have stopped running.

Sittercity Single Sign-On

As Sittercity began developing new APIs to support future mobile applications, a new authentication system to enable cross-platform support was required.

The single sign-on service is designed to support all of Sittercity’s customer accounts across all devices. We choose to use the OpenID 2.0 protocol for authentication, and OAuth 1.0a protocol for authorization. Using open standards for security allowed us to quickly develop clients for the service, including an independent administration tool and clients for Ruby and Objective-C.

In addition to portability, the single sign-on service had to be able to support traffic patterns unique to Sittercity. During development, we performance tested the service using simulations based on real Sittercity authentication traffic. This testing paid off in 2014 when the service supported Sittercity’s busiest high season on record.

Since 2013 the single sign-on service has managed all of Sittercity’s customer authentications. In 2014 the service became the authentication system within the Sittercity API Authentication and Authorization Protocol (SA3P 1.0) specification, alongside an OAuth 2 authorization service. This is now used by the Sittercity web site and native mobile applications.

The service was designed, developed and is maintained by the Sittercity engineering team. It is now a core service, powering all of our authentication experiences. We hope to open source the protocol and applications in the future.


Sitterati is a new mobile product from Sittercity, America’s first and largest online sitter database. Sitterati provides a new and easy way for parents and sitters to manage and pay for child care on the go.

I am currently the Chief Technical Architect of Sitterati, responsible for design and delivery of all the technical aspects of the project. Additionally I manage a small team of very talented developers. This project has been one of the most challenging and rewarding I have worked on in recent years.

Sitterati was publicly launched in the United States in January 2013 for iPhone.


Sport Relief FROST

Comic Relief had to support a large online fundraising community for the Sport Relief 2012 campaign. FROST is a system designed to provide online community fundraising, payment processing and online retail to support Sport Relief. However FROST was also built to provide Comic Relief with a fundraising platform for all of their future campaigns, as well as support for other charities.

I provided the System Architecture for FROST, responsible for designing and specifying the core architecture for the platform. This resulted in a large specification document and a presentation to the FROST development team. I consulted with the development team to provide advice on tooling, frameworks and processes.

Sport Relief 2012 was a huge success raising £67,977,824 for charity. A large portion of the money raised was managed within the FROST system.


Potato Council Wonderfuel Nutritional Calculator

The Potato Council of England were launching a new campaign to promote British potatoes. They decided that rather than commissioning a traditional advertising campaign, they would instead build and distribute and free application. This application would educate the user to the nutritional value of potatoes compared with other foods. When a user discovered a new nutritional fact about potatoes, they can post it to their Facebook wall.

I was approached to provide an answer to the brief supplied by the Potato Council. I submitted a design proposal for an iPad application based on the initial design ideas produced by the Potato Council. The iOS application was built and delivered over two weeks. I provided all the final user interface design and development services. Finally, I was also responsible for the successful submission of the application to Apple for review.


Sittercity is America’s first and largest online sitter database, providing parents with a vast selection of potential sitters in their city. Also helping sitters and nannies find work in their neighbourhoods.

I was the senior software developer responsible for implementing a new authentication service to the platform. The new system used the OAuth 1 authentication protocol, providing authentication services to the entire Sittercity platform. It also provided support for handling remote authentications from other sites and services.

Whilst working on the core Sittercity product, I also was involved in rationalising the registration flows for sitters and parents and implementing a new promotional framework for new registrations.


Kohana is an open source elegant PHP5 HMVC framework that provides components for building web applications. I have been one of the core developers of Kohana since 2008, mostly concentrating on the HTTP request/response architecture and caching.

In 2011 a new major milestone release of the framework was nearing completion. As part of the release we wanted to refresh the Kohana web site. Working with designer Inayaili de León, we collaborated on the new Kohana web site design and build. It was deployed with the release of Kohana Framework 3.2 in the summer of 2011.

OU Annotate

The Open University wanted to provide their students with a new tool that would allow users create annotations on web sites. The annotations created by a user could be either private, or shared with other users of the system, creating a community of users. The tool had to be implemented in javascript to ensure that no special browser plugins were required, and the tool would support the widest possible combinations of browsers.

I was a Technical Team Leader on the OU Annotate development project, initially managing a team of four developers. I provided the high level system architecture for the underlying API supporting the javascript client. Additionally I provided a design specification describing how the javascript client would manipulate the DOM to provide the visual feedback required by the project.

The OU Annotate tool is now available to all students of The Open University. There is a screencast demonstrating the tool in action created by the Product Owner for Open University, Jenny Gray.


BBC iPlayer v3

In 2009 the BBC launched a new development project to migrate the existing BBC iPlayer v2 web site to the new BBC presentation framework. The new BBC presentation framework was a based on Zend Framework version 1, with BBC specific custom extensions. For over a year a BBC internal team developed the new iPlayer v3 service.

In the spring of 2010 performance testing of the new system prompted a new effort to improve the overall performance of the system. I joined the project to help integrate the BBC iPlayer v3 presentation system with a Varnish caching layer. Working with the BBC team we identified the dynamic and static areas of the iPlayer interfaces and devised a caching strategy for Varnish. I was then responsible for implementing the new hybrid presentation layer, integrating the BBC presentation layer with Varnish and javascript.

The BBC iPlayer v3 product launched as a beta in June 2010 and fully replaced the v2 system in September. The product has exceeded all performance benchmarks required by BBC management. As of January 2013, the iPlayer v3 system is still in production.

On a personal note; The BBC iPlayer v3 project was one of the most enjoyable projects I have been involved with. I believe I share the same feeling as the entire team working on this project, that it is one of the projects I am most proud of to this day.

Cable&Wireless Worldwide MyCW

In 2009 Cable&Wireless Worldwide (now part of Vodafone) required a new portal for their enterprise customers. The system would provide a single point of presence for Cable&Wireless Worldwide B2B customers to manage their accounts, report faults with their infrastructure and track the progress of any trouble tickets.

I joined the team in August 2009 to provide the presentation layer integration with a custom built service layer. I designed and implemented a new Service-Relational-Mapping framework (now Open Sourced by Inviqa) to represent the service layer API entities as first class objects in the presentation layer.

In 2010 I became the Technical Team Lead on the MyCW Customer Portal project responsible for all day to day development. During this time I lead a project to improve the overall performance of the entire system by introducing optimisations and Varnish caching across the various service tiers.

The MyCW Customer portal supported a large portion of Cable&Wireless Worldwide’s B2B customers up until their acquisition by Vodafone in 2012.


In 2008 decided they needed to replace their existing PHP4 based web site with a new money transfer platform. This would require a complete re-write of the entire system, which had been continually developed for over four years at that point.

I provided a new system architecture for the money transfer platform that would enable to support their existing customers sending money from the UK to Zimbabwe and South Africa. However, the system architecture also was designed to support money transfers between any two countries globally.

I was responsible for the overall implementation of the new money transfer platform. This included providing the development team with design direction, and providing scalable ways to deal with a seemingly endless list of payment processing companies and banks.

At the end of 2009 the new system launched. Within six months had launched a global money transfer operation supported by the new architecture.


Contact Packaging Online Store

Contact Packaging wanted to expand their existing operations from an antiquated order system that was not online. This required a new online store to be created that would provide a customer experience as well as a back-office administration tool.

I joined the project to provide the system architecture and design for the store and administration system. The system I designed was a custom build based on the specifications supplied.

This was the last project I ever worked on that I did not prescribe using an existing software framework. I am still proud of this project as it was one of my first truly successful systems built from the ground up. But if I were working on this project today, I would have turned to a solution like Magento to provide the backbone of the system. If only Magento was stable when this project kicked off.

Although I had worked on a number of system architectures up until this point, this was the first and last that I designed every single component for without using a PHP framework. For that reason, it will always be one I remind myself of whenever I set off on a new project.