Sean Killeen

A mind at work. Microsoft MVP and passionate .NET dev. Trying to be all the human I can be in the time I have. (he/him)

Work With Sean

I created this page because I receive a lot of contacts from those recruiting for a position. It is meant to complement my LinkedIn profile.

Do you want to know if I’d be a good fit for your organization, or would you like to work together? Read on below to see if we should chat!

My Current Status

I’m embarking on a new opportunity shortly, and therefore am not currently accepting opportunities.

At a Glance

  • Microsoft MVP in Developer Technologies (~100 in this category in the US at last count)
  • 15+ years developing software in the .NET ecosystem
  • Deeply invested in .NET community and supporting OSS
  • Led the modernization of a system that industry analysts called more complex than the moon landing
  • Polyglot developer beyond .NET – comfortable with Javascript (prefer TypeScript), Ruby, Python, and others
  • 5+ years leading teams of between 5-20 individuals
  • Previously certified instructor for ScrumAlliance (CSD) and ICAgile (ICP-TST, ICP-ATA) multi-day courses
  • Lead of the NUnit Documentation project and avid open-source contributor
  • National and Meetup speaker; organizer of .NET DC
  • A history of substantial impact

Outcomes I Provide

  • In-depth expertise and delivery across the .NET / Microsoft ecosystem
  • High-performing, enabled, and engaged teams
  • The growth of leaders within teams and organizations
  • Organizational agility – a culture of learning, experimentation, quality, and collaboration
  • Confidence in code via automated testing and great processes
  • DevOps-related expertise (CI/CD pipelines, operational visibility, robust delivery mechanisms)

Are We a Good Match?

Types of Work

I’m likely a fit for the following types of roles or similar:

  • Technical Leadership: Rallying a team or organization toward an objective and moving things forward is something that’s in my veins. Depending on the organization, this may be a Director, Fellow, Principal, or Technical Manager role (or similar). I am at my best when I’m providing a large impact across teams or an organization and empowering / enabling teams to achieve that impact.
  • Developer Relations: I love forming relationships and speaking / blogging / streaming / teaching about technology and development approaches.
  • Internal / productivity engineering: I delight in being a force multiplier and enabling my colleagues to do their best. Tooling, CI/CD pipelines and systems, removing blockers, etc. I’d probably do best when combining this with some sort of technical leadership capacity, as I believe everyone should be invested in these things.
  • Sales Engineering: I see this as similar to developer relations, in that I love helping potential customers see where they could derive benefit, and I enjoy contributing value to a variety of challenges.

I’m potentially a great fit if…

(You don’t have to check all of these boxes, especially if you’d like me to help move you to that place.)

  • :heavy_check_mark: The position is full-time. I’m looking to find a place I can grow with and make a substantial impact.
  • :heavy_check_mark: You work in the Microsoft / .NET space. I’m comfortable in other arenas but am currently most invested in that ecosystem.
  • :heavy_check_mark: The position is remote, particularly if the organization is remote-first. I don’t mind being in person, but COVID-19 adjusted my priorities.
  • :heavy_check_mark: Your organization is looking to embrace agility.
  • :heavy_check_mark: You want smaller feedback loops. I like to move organizations toward streams of value, working iteratively and incrementally to produce it.
  • :heavy_check_mark: Culture is on the table. I believe people who work at an organization have (and should have) a hand in shaping culture.
  • :heavy_check_mark: I can work in public. I enjoy working transparently in the open. If you happen to build open source software or collaborate in an open format, that’s something I’d be interested in. This is part of the appeal of developer relations / sales engineering for me as well.
  • :heavy_check_mark: I can teach. Whether it’s the general public or my own team, I love learning from others and I love helping to level others up.
  • :heavy_check_mark: I can create content around my work. I tend to create content – tweets, blog posts, demos, streams – around the work I’m doing. It doesn’t have to be part of the day to day, but sharing with the world is very important to me, so it at least shouldn’t be frowned upon. (I’d never reveal anything in confidence, etc. of course.)
  • :heavy_check_mark: You’re at least cloud-curious. The cloud offers a great deal of potential for organizations. If you’re not currently using it, it would be great if you’re at least open to considering the value it can provide.
  • :heavy_check_mark: Your organization has policies that treat staff as humans. Flexible / Unlimited / Mandatory PTO, unlimited sick time, an environment of freedom/trust, etc. are some examples.
  • :heavy_check_mark: You don’t want me to stay “in a lane”. I am someone who loves “honey-combing” to provide value across an organization.
  • :heavy_check_mark: You want ideas for improvement. I have been described as an “idea-dense” person. They’re not all going to be gold, but receptive organizations will benefit the most from me.
  • :heavy_check_mark: You believe that technology delivery is a team sport.
  • :heavy_check_mark: You care about a culture which very much includes Diversity, Inclusion, and Belonging. I have no desire to reinforce harmful status quo or toxic systems of inequality.

I’m potentially not a great fit if…

(It’s OK if you check some of these boxes, especially if you want my help in fixing them.)

  • :x: The position is contract / temporary. I’m only seeking full-time roles where I can invest effort and make an impact.
  • :x: The work is in consulting. I have a background in great consulting impact, but am considering switching things up a bit and bring my full potential and impact to bear on the mission of an organization.
  • :x: I will be stuck using less-than-ideal equipment, especially if I can’t bring my own. While not a game-changer, this usually signals a lack of investment in engineering culture, as the time loss of underpowered hardware vastly outweighs the cost savings.
  • :x: You work with non-civilian government. I want to ensure my personal ethics remain aligned with my work.
  • :x: You are looking for a super-senior individual contributor. While I have the technical skills and can certainly do this as needed, I prefer working with and leveling up teams. Technology delivery is a team sport.
  • :x: You are located more than 30 minutes from Arlington, VA (if not remote). I am a Dad to a little guy and I’d like to spend more of my time at home instead of commuting.
  • :x: Your organization uses SAFe or scaled agile approaches. Honestly? I just don’t think they work, and I think they impede organizational agility. I keep an open mind, though, and you’re welcome to try to change it.
  • :x: You don’t want to move things forward. I am continually seeking to move approaches, technology, and organizational culture forward. It’s how I’m programmed. I’m a realist – these things don’t happen overnight, and I don’t have some grand perfect vision – but if your organization isn’t interested in that, it’s probably not a great fit.
  • :x: You ‘do Agile’ or think there’s one way to be agile. Agility takes many forms and is a continual pursuit.

Clearances

  • I have held Public Trust clearances via both NIST and DHS.
  • I believe I would be clearable at TS/SCI w/poly if need be.
  • I do not currently hold any active clearance (my Public Trust clearances expired along with the work I was doing for those agencies.)

Alphabet Soup – Keywords, General Skills, etc.

Category General run-down 1
Languages C#, TypeScript, Javascript, Ruby, Python, Java
Platforms & Frameworks .NET Core / .NET 5-7, .NET Framework 4.x, ASP.NET, MVC, WebAPI, Akka.NET
Front-end React, Vue, Angular to a lesser extent. Experience with Backbone, Knockout, jQuery
Build Tools GitHub Actions, Azure DevOps, OctopusDeploy, TeamCity, Jenkins, CircleCI, TravisCI, MSBuild
Databases General SQL/NoSQL, SQL Server, Neo4j, CosmosDB, ElasticSearch
ORMs & Migrations Entity Framework, EF Core, Dapper, Roundhouse
Cloud Azure PaaS / SaaS, Serverless, AWS .NET Serverless & Terraform IaC
Infrastructure tooling Terraform, ARM, Bicep
Automated Testing tools NUnit, xUnit, SpecFlow, Moq, FluentAssertions, Bogus, Testcontainers
Automated Testing Techniques TDD, BDD, Gherkin, AATs
Other common libraries FluentValidation
Ticketing and workflows Jira, Trello, GitHub Projects, Azure DevOps, TFS
Static Sites Jekyll, GitHub Pages, Azure Static Sites, Netlify
Methodologies and Mindsets Agility, Scrum, Kanban, DevOps, Lean Product
Leadership Transformational leadership, Leader/leader model

Feedback I’ve Received

Highlights from what my peers recently said about me, anonymously. I am incredibly proud of this feedback, and feel it represents what I can bring to an organization.

Feedback from 2023

“Sean had an amazing year with tremendous impact at [Client] – the team he leads produced at least 15 significant “firsts” for the client and the majority are directly resulting from Sean’s expertise and drive to improve the client’s operational capabilities”

“He also did significant, impactful coaching of client technical staff, demonstrating the art of the possible with modern technologies, tools and engineering practices in a way that created excitement and enablement resulting in numerous new advocates for our team.”

“Sean is the ultimate technical coach and he is single-handedly setting a new standard for technical and organizational practices at our client while bringing people along with a positive message of how learning and collaboration can improve both their individual work and the organization as a whole.”

“Sean is so full of energy and knows so much. He is a very positive influence on the team, and I appreciate his ability to explain conceptual/technical things.  He performs not only as a tech lead, but also as a mentor explaining the WHY behind decisions. He is humble and helps instill the feeling of community, bringing together the diversity of experts and non-experts on the team.”

“Sean is one of the most proactive people that I have worked with. He has often reached out to [Client] folks to try and support us, even presenting a brown bag for [Client] (both clients and contractors). He is a positive, tangible presence at a contract he isn’t even directly on. Having that lifeline does create some psychological safety that is appreciated.”

“In a totally unqualified statement I can say that Sean is the best supervisor I’ve ever had. This is not just best at Excella, this is in my career.”

“he listens deeply, provides thoughtful feedback and encouragement, and by the time I get to the other side of it I have tools and confidence to move forward. Despite the fact that Sean has MSD director and heavy client responsibilities I never feel neglected or that he is phoning it in, which is really impressive to me.”

“Working with Sean I’ve already seen myself become someone more comfortable with receiving difficult feedback, even inviting it so I can improve more honestly instead of relying on self talk as my barometer for how I’m doing. I’ve felt more capable of actually following through on some of my personal career and professional development goals with some of the strategies he’s shared.”

“I’d like Sean to be my supervisor forever.”

“Sean has been instrumental in helping [Client] leadership adopt new ways of doing thing and implementing a lot of firsts at [Client], such as terraform, thousands of automated tests, & event sourcing just to name a few.”

“Above all else, Sean is responsive, helpful, and dependable. In my time at Excella thus far, I know that if I come to Sean with a problem, he has an answer. And if he doesn’t have an answer, he makes it his priority to find one. I know that Sean wears a lot of hats at Excella, but every time that I have interacted with him, he has been able to make my needs a priority.”

“When I first interviewed with Excella, Sean facilitated my technical interview. After that interview, I felt positive that I wanted to work at Excella, heavily due to the opportunity to work with and learn from Sean.”

“Sean is also very transparent, but in a kind way. He cares about the message he is giving and knows when and how to give feedback. I appreciate having Sean as a teammate because he is never afraid to share his opinions, but also respects the opinions of others.”

Feedback from Prior Years

“Though he had many non-client obligations, he was the lead developer on the account and provided great results, value, and impact both to the client and our firm.”

“One of Sean’s strengths at the client is his technical coaching skills. Sean has gathered a lot of skills in his career and he is always willing to lend a hand – usually going above and beyond until his subject feels well-informed and satisfied with the information.”

“Sean’s leadership and mentorship over other developers in 2019 helped to institute a culture of proactivity and a mentality of ownership. He spent countless hours helping more junior developers understand advanced .NET concepts and was a true testament to leader who leads by example.”

“Sean is without question the most productive developer I have ever worked with. He has implemented systems for himself to help his productivity, and shared tips and tricks with the entire team on several occasions. Sean’s leadership on the our project team has helped to grow every colleague for the better, and has inspired all to perform to the best of their abilities.”

“Sean always makes himself available to discuss an issue, listens and understands the issue, gives his recommendation, and works with the person to construct an implementation.”

“Sean again showed his professionalism and expertise through (the CSD certification) class. Going not only throughout the country, but also demonstrating our firm’s technical knowledge and experience to existing and potentially future clients.”

“The project’s work required .NET expertise which Sean brought to the project. Sean had limited time to accomplish the work and, in typical fashion, he documented everything he did and encouraged the same of others. Sean’s contributions allowed the project team to put important improvements in place to move the application toward more automated deployments.”

“Sean is already aware of the constructive criticism I would offer. Sean’s enthusiasm sometimes gets the best of him and he takes on too much. I believe this is a minor thing, because I would not want to see Sean correct this behavior if it meant that his enthusiasm (his superpower) was at all diminished.”

“He has exceptional drive and enthusiasm. It’s contagious and powerful. I appreciate the way he challenges me and others to constantly bring our best selves to our work. I also appreciate how Sean does it; he knows when to broadcast a question or a statement to a broad forum to help clarify all of our understanding. He also knows when a more conservative approach is called for. We have had many direct slack conversations where he has sought out my opinion to refine his own understanding (or give me direct feedback) where appropriate. I think Sean’s discretion and decision-making around his communications is a real strength.”

“There is often tension in our retros, which stems from the team attempting to implement good agile practices, and the client not understanding the value behind the practices, or viewing velocity as a metric of measurement for the team. In these scenarios Sean is able and willing to speak up and articulate the situation and explain the value to the client.”

“The team and myself view Sean as a key thought leader and expert and regularly seek advice from him.”

“He is always willing to make time for questions and explanations. From technical practices to agile practices to managing client relationships, Sean is willing to help others work through the challenges they are facing.”

“This is the third year I’ve had the opportunity to provide third-party feedback about Sean, and this is the third year I will state this truth: Few people have had as profound an impact on my career as Sean. I joined our firm as a very green developer. Sean has been in my corner this whole time. Sean is always an advocate for our firm and his project, but even moreso for his teammates.”

“When I had some tough topics to deal with on my project, Sean offered many suggestions for how to handle it and he was very empathetic. If you are a supervisee of Sean’s, you would be very fortunate to have him because he has good experience and has many thoughts on how he would approach a situation.

“As a result of his advice and guidance, I feel like I’ve grown and become a better consultant. He has helped me to better understand more about DevOps and encourages me to be bolder and have more difficult conversations with coworkers.”

“This year, Sean has coached me through my first technical leadership position. As the lead developer on a special project, I’ve had to navigate things like budgets, deadlines, client internal politics, and direct customer interfacing. It’s my first time facing some of these problems, and Sean – who has a tremendous ability to bridge the gap between “tech” and “people,” has mentored me through the whole process. He’s always willing to listen to me and back me up.”

“This particular team has a fantastic culture, and I feel like a great deal of that back to can be traced back to Sean’s efforts (although he’s probably too humble to admit that.)”

“I’ve gained even more appreciation for the culture change that Sean has driven over the years at the client. In particular, Sean has – over a several year span – driven a massive shift towards agile team processes and team-owned dev ops, despite lots of inertia and resistance. To do so while remaining so positive and beloved among team members (ours and otherwise), is a testament to Sean’s unique leadership skills and ability to astonish.”

“His technical knowledge is very in-depth, and he’s personable and engaging while remaining professional in his demeanor. I look to him as a role model in the most literal sense of the word: one who models the role that he has on the team.”

“He is always willing to share his knowledge and expertise with the team, and leads by example making sure people feel heard, seen and appreciated.”

“To say any team would be better off with Sean on their side is an understatement. Sean affects radically positive change and goes above and beyond to cultivate great careers. He delivers, but also inspires others to deliver.”

“I have always appreciated Sean’s honesty, integrity, and commitment to accountability, maintaining our firm’s culture, and ensuring that we “buy what we’re selling.” He is a personal role model of what it means to be an effective leader and I am a better leader, technologist and person for having known him.”

“His drive is a great inspiration and has for sure motivated me in 2019 to accomplish as much as I have.”

“Sean brought a potential opportunity with a client to the private sector and he contributed heavily to the proposal. Sean wrote the majority of the content, held conversations with his contact, and represented our firm at the client presentation. Throughout, Sean dedicated all of his energy and spare time to the opportunity, even during times when he was sick or tied up with travel and teaching a course.”

“I know that he is someone I can always trust and rely on.”

“Sean is possibly the most genuine and passionate person I have ever had the fortune and pleasure to work with. He cares so deeply about people, culture, leadership, technology, technical delivery/client satisfaction, and the general success of our firm, that I am perpetually astounded at the incredible results he’s able to attain in each of these areas.”

“Sean’s passion in infectious and he is a tribute to the culture of leadership we have at our firm.”

“Sean operates at a level on par with the best our firm has ever employed. In a lot of ways, Sean is the ultimate colleague. Sean brings in BD opportunities, Sean solves technical problems for clients, Sean helps to solve cultural problems across our organization, Sean represents our firm as a technical leader at a myriad of conferences — Sean does it all.”

“Sean was an exceptional supervisor in my opinion. We had constantly 1:1 check-ins during the year were he provided me valuable guidance, feedback and clearly set the expectation about my performance. Sean made himself available even when he wasn’t working at the client to help me if I needed.”

“Another great characteristic of Sean is how he cheers and recognizes individual and Team accomplishments at the client. He is always giving credit to the Team or individuals making sure the client is aware of these accomplishments.”

“But the best thing about Sean isn’t any of that. It’s that you can rely on him. You can count on his ability to hear you out when something’s going wrong. You can rely on his advice to be as unbiased as possible, while still being empathetic.”

  1. This is not an exhaustive list. ↩