Juan DeAngulo was born and raised in South America - then eventually, came to the status in 2017 for college to play Tennis. He kept playing throughout college and into his 40's, at which point he switched to golf and never picked up a racket again. He's been married for 25 years, with 2 older kids - one in law school, and one studying software development. As a family, they enjoy comedy, which funny enough was an acquired taste for Juan. They also love being outdoors, anywhere they can get out and about.

At a prior company, Juan and his team created proprietary algorithms to intelligently predict and tie revenue. These models were based on tried and true processes. While Juan was obtaining an advanced degree at Harvard, his current venture was incubated around predictive revenue, and these algorithms.

This is the creation story of Inselligence.

Sponsors

• Incogni
• NordProtect
• Vention
• CodeCrafters helps you become a better engineer by building real-world, production-grade projects. Learn hands-on by creating your own Git, Redis, HTTP server, SQLite, or DNS server from scratch. Sign up for free today using this link and enjoy 40% off.
• Full Scale
• Paddle.com
• Sema Software
• PropelAuth
• Postman
• Meilisearch

Links

• https://inselligence.com/
• https://www.linkedin.com/in/juandeangulo/

Today, we are continuing our series, entitled Developer Chats - hearing from the large scale system builders themselves.

In this episode, we are talking with Petr Petrenko, Senior PHP Backend Engineer at Bumble. Petr will take us through his developer journey, in working on large scale backends, managing the tension between stability and innovation, and designing systems to interact with culturally different economies.

Questions

• You’ve worked on large-scale backends that serve millions of users. At what point do systems start to outgrow the teams that built them?
• At some point, every mature backend reaches a stage where rewriting is no longer realistic. How do you recognize when a system has crossed that line, and what’s the right way to handle it?
• There’s always this tension between stability and innovation. How do you decide when a system needs refactoring versus when you just need to live with the technical debt?
• Let’s talk about the human side of legacy systems — what have you learned about culture, documentation, and knowledge transfer that keeps old systems alive and reliable?
• You’ve also built and maintained complex payment systems for global users. What’s something most engineers underestimate about cross-border transactions?
• When you’re designing systems that deal with different currencies, laws, and tax regulations, how do you balance the technical with the ethical — for example, user privacy or data sovereignty?
• For engineers listening who want to build something durable — not just fast — what advice would you give about writing code that will still make sense years from now?
• One of your most impressive projects is a high-performance image-matching system you built yourself, capable of scanning tens of millions of images with sub-second results. Can you walk us through the moment you realized you needed to redesign the system — and what engineering choices made that level of performance possible?
• You’ve also worked on billing systems and fraud mitigation at scale. Was there ever a moment when you had to choose between a technically “clean” solution and a solution that better protected users or the business? How did you make that call?

Sponsors

• Incogni
• NordProtect
• Vention
• CodeCrafters helps you become a better engineer by building real-world, production-grade projects. Learn hands-on by creating your own Git, Redis, HTTP server, SQLite, or DNS server from scratch. Sign up for free today using this link and enjoy 40% off.
• Full Scale
• Paddle.com
• Sema Software
• PropelAuth
• Postman
• Meilisearch

Links

• https://www.bumble.com/
• https://www.linkedin.com/in/petr-petrenko-006534150/

Sarah Lucena lives in San Francisco, and starts here day at 4:30 am to lead her LATAM team. She's originally from Brazil, born and raised on the north east side of the country. She studied in South Paulo, and spent 5 years in Uruguay, which was a huge influence in her career today. Outside of tech, she is a big cat lover, having 2 at her home. When it comes to Brazil, she recommends people visiting Rio, which condenses everything good about Brazil into one city.

In the past, Sarah felt empty at her job. In other words, she was not happy with the legacy she was leaving. She built her team many times over, but was not able to create a team with the chemistry she was looking for. And the solutions for recruiting were supremely focused on the wrong signals for these types of connections.

This is the creation story of Mappa.

Sponsors

• Incogni
• NordProtect
• Vention
• CodeCrafters helps you become a better engineer by building real-world, production-grade projects. Learn hands-on by creating your own Git, Redis, HTTP server, SQLite, or DNS server from scratch. Sign up for free today using this link and enjoy 40% off.
• Full Scale
• Paddle.com
• Sema Software
• PropelAuth
• Postman
• Meilisearch

Links

• https://mappa.ai/
• https://www.linkedin.com/in/sarahaluc/

Tucker Calloway grew up in Alamo, California, in the Easy Bay Area. And has returned to that area to raise his family - 25-30 minutes outside of the San Francisco area. He studied computer science at Cal, but eventually moved into sales engineering - and then sales. But outside of tech, he is married with 2 kids - one in college, and one in the latter years of high school. There is lots of change going on his family's life right now, but Tucker finds time to do woodworking and build his own cabinets.

Ten years ago, a couple of co-founders built a solution to make log management easier for developers. Tucker joined that company in the past, and observed the dynamics of the industry and the company. They all decided that to take the business of the next level, they needed to change the physics of observability.

This is the creation story of Mezmo.

Sponsors

• Incogni
• NordProtect
• Vention
• CodeCrafters helps you become a better engineer by building real-world, production-grade projects. Learn hands-on by creating your own Git, Redis, HTTP server, SQLite, or DNS server from scratch. Sign up for free today using this link and enjoy 40% off.
• Full Scale
• Paddle.com
• Sema Software
• PropelAuth
• Postman
• Meilisearch

Links

• https://www.mezmo.com/
• https://www.linkedin.com/in/tucker-callaway-9310171/

Hojjat Jafarpour lives with his family in California. He got his PhD in databases and data streaming, back when the landscape was different and data streaming wasn't "cool" yet. He was an early member at Confluent, but also spent time at Quantcast, Informatica, and NEC Labs. Outside of tech, he has a family with young kids. He enjoys traveling, and can't wait until the kids are old enough to take on big trips.

Hojjat joined Confluent in their early days. He was on a project that built out kSQL, which was a key cornerstone of Confluent. As these were the early days of stream processing, he started to think about ways to make it easier - to make this sort of tech available without all the infrastructure.

This is the creation story of DeltaStream.

Sponsors

• Incogni
• NordProtect
• Vention
• CodeCrafters helps you become a better engineer by building real-world, production-grade projects. Learn hands-on by creating your own Git, Redis, HTTP server, SQLite, or DNS server from scratch. Sign up for free today using this link and enjoy 40% off.
• Full Scale
• Paddle.com
• Sema Software
• PropelAuth
• Postman
• Meilisearch

Links

• https://www.deltastream.io/
• https://www.linkedin.com/in/hojjatjafarpour/

Today, we are kicking off a new series, entitled Developer Chats - hearing from the large scale system builders themselves.

In this episode, we are talking with Svyatoslav Babinets, Engineering Manager at Meta. Svyatoslav helps to illuminate teh approaches he takes when building larger scale systems, connecting millions of users, and motivating users and developers alike.

Questions

• You’ve worked on everything from large-scale multiplayer worlds to social technologies that power digital presence — how did that journey shape the way you think about engineering today?
• You’ve worked on systems that connect millions of users across different platforms and products. How do you design architecture that supports high development velocity in large teams while still delivering experiences that delight users?
• In your experience, what helps large companies move faster without sacrificing quality? Can you share how approaches like Virtual mission squad enable cross-functional collaboration across different disciplines and tech stacks?
• As systems and teams grow, platform solutions often become the glue that holds everything together. How do you approach designing and implementing platform architecture that supports autonomy while keeping the whole ecosystem consistent?
• From your experience, where do culture and infrastructure intersect? What kinds of engineering decisions are really decisions about trust, not technology?
• You’ve worked both in games and in metaverse projects. What do these worlds teach us about building systems that feel alive — where motion, identity, and emotion all need to synchronize?
• Large-scale systems evolve constantly. How do you design for long-term adaptability — ensuring that architecture remains flexible and scalable as product and user demands grow?
• Looking ahead, how do you see the future of human–digital interaction? What should the next generation of engineers focus on — performance, presence, or empathy?

LInks

• https://www.meta.com/
• https://www.linkedin.com/in/svyatoslav-babinets-42b826137/

Spriha Baruah Tucker has spent time in a number of places - growing up in India, attending boarding school in Singapore, and now living in San Francisco. She spent many years at Google, before founding her own startup called Aviator. Outside of tech, she really likes music, having a soft spot in her heart for Bollywood, but really digging into the jazz world these days. She enjoys the guilty pleasure of trashy romance TV, and tends to travel to get the best food - her favorite being Nashville.

Spriha was a founder at Aviator, and was made aware of her current company while serving her customers. He noticed that all of her customers who used this platform absolutely adored it, to the tune of making infomercials for the platform. She reached out to the founder to let him know... and the rest is history.

This is Spriha's creation story at Buildkite.

Sponsors

• Incogni
• NordProtect
• Vention
• CodeCrafters helps you become a better engineer by building real-world, production-grade projects. Learn hands-on by creating your own Git, Redis, HTTP server, SQLite, or DNS server from scratch. Sign up for free today using this link and enjoy 40% off.
• Full Scale
• Paddle.com
• Sema Software
• PropelAuth
• Postman
• Meilisearch

Links

• https://buildkite.com/
• https://www.aviator.co/
• https://www.linkedin.com/in/spriha-tucker/

Gajus Kuizinas lives in Mexico City, and travels between there, New York and San Francisco. He had a non-traditional upbringing for an engineer, as all of his family were into the arts - so he had to make his own way. He started in Lithuania, and eventually was recruiting to setup computers and networks for dating platforms. Eventually, he got into freelancing, and started his first startup in the UK. Outside of tech, he has a garden, which doubles as an ecosystem for his free roaming hedgehog and bunny.

Gajus started to think about the arc of becoming a freelancer. He realized that everyone who goes through a journey as a freelancer feels like a cog in the machine, and falls off the marketplaces out there. He realized that there was a massive vacuum and gap in the internet for these folks that needed to be filled.

This is the creation story of Contra.

Sponsors

• Incogni
• NordProtect
• Vention
• CodeCrafters helps you become a better engineer by building real-world, production-grade projects. Learn hands-on by creating your own Git, Redis, HTTP server, SQLite, or DNS server from scratch. Sign up for free today using this link and enjoy 40% off.
• Full Scale
• Paddle.com
• Sema Software
• PropelAuth
• Postman
• Meilisearch

Links

• https://contra.com/
• https://www.linkedin.com/in/gajus/