Clojure in Product. Would you do it again?

Episode 12 of "Clojure in product. Would you do it again?" is live — Marcin Maicki, Global Data Developer & Lead Developer at Dentons, joins Artem Barmin and Vadym Kostiuk to talk about running Clojure inside a large, decentralized enterprise.

Highlights:

- Marcin’s Clojure origin story: started with ClojureScript, moved into Clojure, and found the functional mindset a natural fit coming from React.

- How Clojure landed at Dentons: a conscious choice for a focused referral‑network venture that valued expressiveness and small teams.

- Practical stack and ops: Postgres, Elasticsearch, Reagent/Re‑frame + Material UI, Metabase; Marcin also works on PySpark/Databricks in his global data role.

- Maintenance and risk: why they’re migrating away from old, unmaintained libs; regular security scans and external testing make dependency health a real concern.

- Team, onboarding, and hiring: a small Clojure pod (Marcin + one dev, testers, DevOps); knowledge sharing, docs, and close pairing are the onboarding tools — hiring remains the main practical blocker.

- Enterprise realities: polycentric org structure, integration friction with firm standards (Power BI, Azure), and the tradeoffs that make Clojure a strong fit in some contexts but a harder sell in others.

Watch Episode 12 to hear the full conversation and the nuances of keeping a nine‑year Clojure codebase healthy in a corporate setting.

In the 11th episode of "Clojure in product. Would you do it again?", Artem Barmin and Vadym Kostiuk speak with Jeremiah Via, Staff Software Engineer at The New York Times. Jeremiah describes how Clojure was introduced and adopted across the search stack at a major media organization, and why JVM interop and practical tooling made it the right choice for their data-processing workloads.

Our conversation walks through concrete topics: Jeremiah’s Clojure origin story, the iterative migration from PHP, Erlang, Python, and Java to JVM/Clojure services, and the search team’s day-to-day work, including how they push vector embeddings into Elasticsearch for AI features and performance.

We also dig into hiring and engineering practices: onboarding newcomers with an emphasis on functional thinking and REPL workflows, hiring for search/domain expertise over prior Clojure experience, maintaining code discipline, and addressing production concerns like memory sizing and performance tuning. As Jeremiah notes, "Now with AI stuff, people can be productive very fast without understanding it, using a cursor and tools like that," and he cautions that it remains to be seen how this will affect the deeper mental model of learning to think in Clojure.

We conclude with Jeremiah's response to a question from our previous guest, Cam Saul from Metabase.

Listen to our podcast and get more insights about Clojure in product: https://www.freshcodeit.com/podcast

Welcome to the 10th episode of our podcast, "Clojure in product. Would you do it again?", where Artem Barmin and Vadym Kostiuk speak with Cam Saul, Chief Architect at Metabase, an open-source business intelligence platform. In his role, Cam wears multiple hats, including reviewing architectural documents, managing developer tasks, and writing custom linters to ensure code quality.

We discuss the integral role of Clojure in Metabase's development and how transitioning from Python allowed the team to ship features much faster. Cam also shares insights into the blend of Clojure and JavaScript developers, highlighting the advantages of Clojure's stability, which enables the team to build upon existing work without the frequent changes seen in other programming environments.

The open-source foundation of Metabase has fostered a collaborative culture that attracts external contributors, some of whom joined the team after submitting valuable requests. Cam reflects on the journey of hiring Clojure developers, emphasizing the learning opportunities it provides. We conclude with Cam's thoughts on the Clojure community and his response to a question from our previous guest, Alexander Johannes from JustOn.

Worth your attention:

• Fast in-product analytics: metabase.com
• Freshcode Clojure Team: freshcodeit.com/services/clojure-development-company

In the 9th episode, we welcome Alexander Johannes, Head of Development at JustOn, a German fintech company specializing in developing Salesforce accounting solutions since 2010. We discuss the nuances of building software for the AppExchange marketplace and the significance of Clojure in niche markets.

What started as a hobbyist's passion for solving intriguing problems like parser development has evolved into the full integration of Clojure into the tech stack, laying the foundation for JustOn's current projects. As Alexander noted, "It opened up the possibilities to be faster and deliver something meaningful."

Learn how JustOn's development team, under Alexander's leadership, developed and maintained the backend in Clojure, including business logic, mass data transformation, and platform integrations. We also walked through a series of questions about project structuring, software testing, hiring practices, overengineering, and team culture. When asked, "Would you choose Clojure as the main tech stack for your next product?" Alexander confidently said, "I would say yes," emphasizing their experience as underdogs in a niche market and the advantages that Clojure provides compared to mainstream technologies like Java.

Listen to our podcast and get more insights about Clojure in product.

In the 8th episode, meet our guest Jereme Corrado, the former CTO of Mobot and a Clojure enthusiast since 2016. Jereme shares his extensive programming journey, emphasizing the importance of quality engineering and the challenges and rewards of adopting Clojure.

Clojure acts as a filter for hiring skilled developers genuinely interested in the language. We discussed the same idea in the 3rd episode: when interviewing seasoned Clojure developers, you can always learn something new. This aspect is critical in building a strong engineering team, especially in startup environments.

Jereme describes successful projects he has worked on, how Clojure popped up on his radar, and how he introduced it to the team. Listen to this episode to know if Clojure matters and what unique strengths and weaknesses it represents.

Worth your attention:

• Structure and Interpretation of Computer Programs: https://web.mit.edu/6.001/6.037/sicp.pdf
• Clojure Yetibot: https://yetibot.com
• Freshcode Clojure team: https://www.freshcodeit.com/services/clojure-development-company

In the 7th episode, we speak with Nathan Marz, founder of Red Planet Labs and creator of Apache Storm, about his 15-year programming journey and the challenges of building scalable systems in Clojure. Nathan shares his experiences with Clojure and his innovative work on Rama, a platform designed to simplify software development.

Our conversation covers testing techniques like with-redefs for debugging, the challenges of hiring Clojure developers, and the architecture's approach to event sourcing and materialized views. Nathan explains why Clojure was the ideal choice for Rama and highlights his team's learning curve and the need for strong engineering expertise.

Worth your attention:

• https://paulgraham.com/avg.html
• https://storm.apache.org/releases/2.2.1/Clojure-DSL.html
• https://redplanetlabs.com/
• https://blog.redplanetlabs.com/2021/06/03/tour-of-our-250k-line-clojure-codebase/
• Blog posts:
  • Deep dive into how we reduced the line count for building the Twitter consumer product at scale by 100x: https://blog.redplanetlabs.com/2023/08/15/how-we-reduced-the-cost-of-building-twitter-at-twitter-scale-by-100x/
  • Introduction to Rama's Clojure API: https://blog.redplanetlabs.com/2023/10/11/introducing-ramas-clojure-api/
  • Post focused on Rama's new programming paradigm https://blog.redplanetlabs.com/2024/10/10/rama-on-clojures-terms-and-the-magic-of-continuation-passing-style/
  • Introduction to Rama's instant migrations and how they work https://blog.redplanetlabs.com/2024/09/30/migrating-terabytes-of-data-instantly-can-your-alter-table-do-this/

#clojure #productdevelopment #java #c++ #softwaredevelopment #freshcode

The sixth episode of our podcast is here! Join us in speaking with Yehonathan Sharvit, author of "Data-Oriented Programming: Reduce Software Complexity." This episode is packed with inspiration and practical advice from Yehonathan, who currently works in cybersecurity, where Clojure plays a crucial role in CyCognito's tech stack. We hope you find valuable insights for your product's journey in our podcast.

Yehonathan shares his transition from C++ and Java to Clojure, highlighting some challenges he experienced early in his career with C++ and MATLAB. We explore how Clojure's elegance and productivity reignited his passion for development, inspiring him to write books and create tools to simplify language learning.

We also emphasize the importance of having seasoned Clojure engineers on a team to navigate complex challenges and enhance junior developers' understanding of this technology.

Worth your attention:

• Practical Common Lisp
• Data-Oriented Programming
• Get Programming with Clojure
• Taking the Attacker’s View
• Freshcode Clojure team:

Welcome to the fifth episode of "Clojure in product. Would you do it again?" Our guest, Jeffy, Lead Backend Developer at HolidayPirates, joins hosts Vadym Kostiuk and Artem Barmin. With 18 years of web development experience, Jeffy shares his journey into Clojure, which he adopted as the primary language for his team during the COVID-19 pandemic.

We touch upon the significance of keeping software simple and focused, advocating for a balance between pure functions and stateful code. As Jeffy reflects on his experience in hiring for niche technologies like Clojure, he shares strategies for identifying passionate developers willing to embrace this unique language.

Worth your attention:

• Search & Book Your Dream Holiday: https://www.holidaypirates.com
• Getting Clojure: Build Your Functional Skills One Idea at a Time: https://www.amazon.co.uk/Getting-Clojure-Russ-Olsen/dp/1680503006
• Russ Olsen: http://russolsen.com
• Learn Reitit and Clojure: https://www.learnreitit.com/
• Calva User Guide: https://calva.io/
• Mastering Clojure Macros: https://www.amazon.co.uk/Mastering-Clojure-Macros-Cleaner-Smarter/dp/1941222226/ref=asc_df_1941222226/?tag=googshopuk-21&linkCode=df0&hvadid=696285193871&hvpos=&hvnetw=g&hvrand=15871465362452006113&hvpone=&hvptwo=&hvqmt=&hvdev=c&hvdvcmdl=&hvlocint=&hvlocphy=9044966&hvtargid=pla-2281435176618&psc=1&mcid=b0e47956d53335e3b589ce46caaa25cd&hvocijid=15871465362452006113-1941222226-&hvexpln=74&gad_source=1
• Freshcode Clojure team: https://www.freshcodeit.com/services/clojure-development-company

In the 4th episode, meet James Trunk, VP of Engineering at Griffin and co-creator of the Polylith architecture, sharing his experience using Clojure in the banking sector. Discover the benefits of using Clojure in fast, high-stakes environments and how it fits Griffin's banking-as-a-service strategy.

Hosts Vadym Kostiuk and Artem Barmin discuss leadership dynamics with James, such as how a skilled team of Clojure engineers encourages creativity and autonomy through smart decision-making. Tune in to learn about the challenges and successes of navigating the Clojure ecosystem and its potential to shape the future of technology.

• https://www.youtube.com/watch?v=nt_cMdqqaPE
• https://www.youtube.com/watch?v=hmQujxmZBck
• https://www.youtube.com/watch?v=SxdOUGdseq4
• https://www.youtube.com/watch?v=ShEez0JkOFw
• Learning ClojureScript: https://www.packtpub.com/en-us/product/learning-clojurescript-9781785887635?srsltid=AfmBOorki4i1f8d7KoBtKYxNDE34D10rkvHHocC40XFbhQJNQcwfp7dh
• Building a thoughtful engineering culture: https://griffin.com/blog/thoughtful-decision-making-is-the-key-to-high-performing-engineering-teams
• Freshcode Clojure team: https://www.freshcodeit.com/services/clojure-development-company

#clojure #productdevelopment #freshcode #griffin #developers

In the third episode, join our hosts Vadym Kostiuk and Artem Barmin as they walk through the journey of Marten Sytema, founder at Catermonkey, a solo engineer turned product creator. Explore Marten's vision about Java, Haskell, and Python, his passion for Clojure, and how this technology transformed his approach to software product development. Marten told the story behind CaterMonkey, a smart CRM solution for catering businesses, and the competitive edge Clojure offered for his company.

We highlight the practicalities of building a startup with Clojure, both challenges and triumphs, including hiring practices, effective use of technology, and fostering a productive development culture.

• CaterMonkey CRM: https://catermonkey.com
• Simple Made Easy: https://www.infoq.com/presentations/Simple-Made-Easy
• Freshcode Clojure team: https://www.freshcodeit.com/services/clojure-development-company

#clojure #productdevelopment #productmanager #python #java #haskell