What is CaaS? What is a Fractional CTO?

Do you have a great idea for an app, but you don’t have any idea how to implement it?

Have you developed your first app using low-cost developers, and now you realize that the design is inadequate for the next stage of your product?

Do you need someone with many years of senior technical leadership to help you meet with investors, help you evaluate vendors, help you do technical roadmaps and design, and maybe to even code up your first app?

Do you want someone when you need them, and not have to be tied to long-term contracts? Do you need to be flexible, and only pay for what you need?


A partial list of past clients includes:

  • Mosiak (real estate)
  • Cohere (wellness services)
  • WeAreRobyn (female health services)
  • Arnie (ESG Investing)
  • XP Investments (trading)
  • Xureal (gaming)
  • Havas Health (healthcare)
  • Story2 (education
  • Blossom (coaching)
  • Kalpsys (Zocdoc competitor)
  • Purple Ant (Insuretech and IoT)
  • Golden Pear (legal financing)
  • Blue Apron (food prep)
  • OneEleven (financial wellness)
  • Namely (payroll)
  • and more …

CTO as a Service (CaaS) is run by Marc Adler, the former Chief Architect and CTO of Citigroup, MetLife, XP Investments, and ADP, and former CTO of various startups (and former classical percussionist). After many years of running large and small technical organizations, I am now available to help your company to develop and troubleshoot your technical team and help you bring your ideas to fruition. If you need someone to code up your application or MVP, I can even get down and dirty with the code.

My axe: M150 Marimba

You only pay for the services you use

A basic tenet about using Cloud Computing is that you pay for what you use. If you just need a little bit of computing power, then you only pay for the actual services that you use. If you are a business whose busy period comes several times a year, then you pay for a lot of computing power only during those times, and the rest of the year, you only pay to “keep the lights on”.

Just like working with Amazon Web Services or Microsoft Azure or Google Compute Cloud, you only pay CTO as a Service for the time you use us. Unlike engaging a major IT consulting firm, there are no long-term contracts that you get locked into. If you need us to work with us for 20 hours a week, then that’s what you pay for. If you want to keep us on a monthly retainer to meet with your development team once a week, that’s all you pay for. If you need to bring us to a meeting with investors, then you just pay us for the meeting. And, if you want to engage us more, then you just have to pay for those increased hours. In this way, you can think of CaaS as you think of your lawyer or accountant.


Below is a video of a roundtable that I did with CTO Craft on February 2, 2023, in which I describe my life as a fractional CTO.




Contact CaaS

If you think that my background can help your organization, feel free to contact me at info@ctoasaservice.org.

(Site Header photo: Futurama Exhibit, 1964 World’s Fair)


How I Can Help You

You might need a Chief Technical Office (CTO) or a Chief Architect (CA), and not even realize it. And wouldn’t it be great if that CTO could write code, and help you develop your product and have the “chops” to face off with your existing developers?

Here are some of the ways that CaaS could help you.

  • Vision: Helping you realize your vision by helping to assemble a development team and leading them to develop a product
  • Innovation: Taking an existing product and helping to move it to the future state
  • Opinions: Assessment of your current applications and development organization
  • Confidence: Meeting with investors. Often times, an investor will be more comfortable knowing that there is someone with a lot of senior-level experience behind the scene.
  • Design: Architecting and designing systems, especially cloud-based systems
  • Refactoring: Transforming your system into microservices
  • Hacking: Writing production-quality code
  • Documentation: Writing technical roadmaps and white papers
  • Faceoffs: Performing product evaluations
  • Due Diligence: Vetting vendors, and facing off with CEO’s, CTO’s and Chief Architects from other organizations

These are some of the companies where I have held senior technical leadership positions.

Some of my Past Work

Realtime Trading Anaytics Dashboard

As Chief Architect of Citigroup’s Equities Division, I was asked to develop one of the first real-time trading analytics systems on Wall Street. It was one of the most compelling uses of Complex Event Processing and Microsoft’s WPF’s technology and was eventually used by the office of the CEO at Citi. You can read more about my work here.


As Chief Architect and Head of Platform at Quantifi, I developed an entire .NET-based Microservices framework from scratch. To the right, you can see the Service Manager Console, which lets an admin view, control and monitor the various services. You can read more about my work with Microservices here.

Service Manager Console for Microservices


Crude Products Pipeline Optimizer

As the Intermin Head of IT at British Petroleum’s Energy Trading operation in Chicago, I found that the Schedulers were losing money on non-optimal scheduling decisions and the use of individual home-grown tools (mostly Excel spreadsheets). I created a pipeline optimization platform which allows optimal scheduling of the transportation of crude products.


In a large corporation which had hundred of systems, I wrote a CMDB (Configuration Management Database)  that kept track of the dependencies between the systems and, for the first time, allowed the IT Enterprise to figure out the effect of a single failure on the downstream systems. Utilized a custom graph query language that I developed.

Our Story and Mission

Man, have I seen it all !!! Over the years, as Chief Architect and CTO of various companies, I have been in the front row at some pretty interesting times. Hedge funds, trading shops, large banks, and insurance companies …. but even small EdTech companies and startups.

I wrote one of the very first word processors for Unix, showing it off at the first UnixExpo in New York. I was one of the first Windows developers on Wall Street. I created a software development company that came out with a series of successful products. My office on the trading floor at Citigroup gave me a first-hand look at the financial crisis. I was asked to join the creation of a brand new investment bank. My professional life has been nothing short of interesting and diverse.

After all these years, I had finally reached some milestones which I set out to accomplish when I first joined the workforce. Instead of picking a nice quiet beach to relax on, I have decided to reinvent myself, and use my years of technical leadership experience to help ….. well, hopefully, you!

Since my title has been CTO and Chief Architect, people seem to think that I know something about technology. Colleagues and family alike have known people who have had ideas about coming up with a great application. And they have sent these people to me, in the hopes that I could help them realize their visions and assist them with building a product.

Because of my obligations to run the technical organization of my employers, I have often had to help these visionaries as a side project. I have helped them hire development teams, I have written some prototypes (yes, I still try to code every day), and I have helped them with the product and technical vision.

Now that I have left the corporate world behind, I would like to bring my years of experience as a CTO, Chief Architect, Engineering Manager, and Developer to help you with your company, be it a one-person startup or a 300,000-person corporate behemoth.

If what I have done interests you, and you need help in developing a product or getting your IT organization in better shape, have a look at my resume and let me know if I can help you.